Lachlan passed away in January 2010.  As a memorial, this site remains as he left it.
Therefore the information on this site may not be current or accurate and should not be relied upon.
For more information follow this link


(This Webpage Page in No Frames Mode)

Welcome to Lachlan Cranswick's Personal Homepage in Melbourne, Australia

Scanned images/text (Chapters 1 to 11, and 19) of "Laboratory Instruments, Their Design and Application" (1960) by A. Elliott and J. Home Dickson

(Second Edition revised, 1960, Chemical Publishing Company - OCR'ing yet to start)

(Put on the Internet with the permission of the estate of A. Elliott)

"Laboratory Instruments, Their Design and Application, 1960" homepage is at http://lachlan.bluehaze.com.au/books/elliott_dickson_lab_instruments/

[Back to Lachlan's Homepage] | [What's New] | [London free Concerts, talks, lectures]

(The following PDF file is quite large, and the internet link moderately slow, so you may have to be patient for it to download)

(Chapters 1 to 11, and 19) of "Laboratory Instruments, Their Design and Application" (1960) by A. Elliott and J. Home Dickson as an Adobe PDF file of the JPG images


Recommended and recently published books on Laboratory Instrument design and control


(Chapters 1 to 11, and 19) "Laboratory Instruments, Their Design and Application" by A. Elliott and J. Home Dickson (Second Edition revised, 1960)



[Scanned image of Page ii]

Title page


[Scanned image of Page iii]

Title page [cont'd] and Preface to the Second Edition

PREFACE TO THE SECOND EDITION

THE demand for a second edition has given us the opportunity to revise the book very completely, correct some doubtful points, bring the matter up to date and add much new material. The chapter on properties of materials has been expanded to include a fuller account of plastic materials, in which field there have been important developments. The same chapter also introduces the subject of corrosion-resisting metals, and a complete new chapter has been added on the subject of corrosion in laboratory instruments. Personal experience has shown how troublesome corrosive agents may be in some laboratories, and it is hoped that this chapter will be of value to many.

Some new figures have been prepared to amplify the section on cross-spring pivots, which are finding new applications as they become better known, and additional figures have been added to illustrate the subject of errors in instruments. The appendix on optical crystals has been enlarged into a chapter with the latest possible information on the refractive index of materials useful in infra-red spectrometry. A complete new section on radiation has necessitated another new chapter which includes the section on photometry. Some new matter has been added on colour vision, to the diagrams of photographic lenses, and in the chapter on photography. Photographic resolution has been treated much more fully.

Some new information on glass protection against radiation hazards which arrived too late for incorporation in Chapter 12 has been added as Appendix IV.

As in the first edition, we have confined ourselves almost wholly to mechanical and optical matters, since any adequate treatment of electronic instruments would have made the scope of the book much too wide.

The revisions and additions have been prompted by the many helpful criticisms and suggestions of friends and colleagues to whom we are very grateful. Research units and establishments in many parts of the world and many firms have also suggested improvements


[Scanned image of Page vi]

Preface to the Second Edition [cont'd] and Preface to the First Edition

which we have endeavoured to include and have provided us with much interesting new matter. We hope that this new edition will prove to be a considerable improvement on the first edition.

A. ELLIOTT
J. HOME DICKSON


PREFACE TO THE FIRST EDITION

THE present-day trend towards specialisation is making it more difficult for students in Universities and Technical Colleges to obtain the wider general training which is so necessary for successful research work.

In any research organisation the worker is often called on to design and construct his own instruments or to guide others in their construction, and he finds his training inadequate to cover the many ramifications involved in this aspect of the work.

It is especially to provide some guide to these ancillary processes and components that this book has been written. The chief aim has been to present the principles on which good design is based, and many examples of the application of the principles have been given. No attempt has been made to cover the entire field of instrument design, but the authors have endeavoured throughout to show the interrelation of good design, material, and method of construction, so that the best results may be obtained with moderate or limited means.

The first few chapters deal with the properties of various materials and their treatment and use in the construction of instruments. A number of workshop processes are described and the accuracy attainable in the various processes is discussed. There is a chapter on the preparation of drawings for workshop use and their reproduction. Succeeding chapters are devoted to methods of construction to suit special requirements and in particular the kinematic design of instru- ments is treated at some length. Chapters on vibration insulation, sensitivity and methods of measurement follow.

Since optical instruments of many kinds and photography play such a large part in modern research work the remainder of the book is concerned with such instruments and methods. Chapters on glass and on the uses and working of glass are followed by a description of a number of optical instruments and devices. There are many tables and diagrams illustrating the uses of lenses, mirrors and prisms and there is much information which is not generally included in books on optics or in the normal college courses. Finally there is a chapter on the applications of photography and several appendices containing miscellaneous information.


[Scanned image of Page viii]

Preface to the First Edition [cont'd] and Acknowledgements

In compiling such a book, based as it is on the accumulated experience of the authors, during many years of research work, there must necessarily occur many items of information collected from a number of sources. Copious references and acknowledgements have been made throughout the book and there has been added a collected list of acknowledgements but the authors must repeat here that they are indebted to many others whose names may not occur in these lists and we take this opportunity of thanking all those whose help, through the years, has made this book possible.

A. ELLIOTT
J. HOME DICKSON


[Scanned image of Page x]

Acknowledgements [cont'd]


[Scanned image of Page xii]

Contents

Preface to Second Edition (Page v)

Preface to First Edition (Page vii)

Acknowledgements (Page ix)

1. GENERAL CONSIDERATIONS (Page 1)

2. THE ACCURACY ATTAINABLE IN MACHINING OPERATIONS (Page 4)

Nominal size, tolerance, limits, allowance. Limits of accuracy to be expected in turning. Plain milling. Surface grinding. Centre grinding. Lapping. Spinning. Location of holes with respect to other holes and to edges and surfaces.

3. PROPERTIES OF MATERIALS USED FOR GENERAL CONSTRUCTION OF INSTRUMENTS (Page 17)

Wood: pine, mahogany, teak, afrormosia, iroko, boxwood, plywood. Metals: wrought iron, mild steel, Case hardening: hard or carbon steel, Grades of Carbon Steel: Stabilization: Alloy Steels. Cast iron: grey cast iron, white cast iron, nodular or spherulitic graphite cast iron. Internal damping. Stainless steel and iron. Staintess cutlery steel. Austenitic steels, Iron-nickel alloys-"Invar". Copper alloys: cartridge brass, Munts metal, turning brass, clock brass, Admiralty gunmetal, porous bronze. Aluminium and aluminium alloys: aluminium, aluminium alloys, duralumin, Y-alloy, Hiduminiurn R.R.50, D.T.D. 424. General remarks on the use of light alloys. Corrosion-resistant metals (non-ferrous). Plastic materials: phenol formaldehyde resin, polymethyl methacrylate, polystyrene, polyethylene, polytetrafluorethylene, polyvinyl chloride, silicone elastomer. Materials for springs: elastic properties, steel, phosphor bronze, beryllium copper, fused silica.

4. CASTING AND JOINTING OF METALS (Page 56)

Casting, jointing, soldering and brazing. Welding: electric welding, flame welding, flame cutting. General observations on welding. Resin-bonded construction: Araldite Type L Cold-setting Araldite. Jointing by mechanical means: rivets, screws, locking of screws and nuts. Relative advantages of cast and built-up work.


[Scanned image of Page xiv]

5. PREPARATION OF DRAWINGS (Page 7l)

Materials for drawing. Assembly and detail drawing. Method of projection: types of lines, scale, sections, screw threads. Dimensions and tolerances. Reproduction of drawings.

6. CONSTRAINED MOTION AND CONSTRAINTS (Page 79)

Kinematic or geometric Design: degrees of freedom, motion of translation, body without freedom. General remarks on geometric design. Accuracy of performance of geometrically constrained mechanism. Modifications to geometric design. Constrained motion employing elastic deformation. The cross-spring pivot. Effect of large deflections: strips giving parallel motion. Springs and clamps.

7. THE MAGNIFICATION OF SMALL DISPLACEMENTS (Page 109)

Mechanical methods: lever magnification. Rolling cylinder and related methods. Parallel deformable strips. Ratchet and toothed wheels: dial gauges, liquid levels. Conditions affecting liquid levels, mounting of levels. Liquid levels for magnifying small movements. Magnification by optical methods: magnification by optical lever, observation of angular movement of light beams. Telescope and scale. The auto-collimator. Moir6 fringes. Interference methods. The thermal relay. Photo-electric relay. Electrical methods.

8. SENSITIVITY AND ERRORS OF INSTRUMENTS (Page 135)

Sensitivity of instruments. Errors. Systematic errors. Errors due to imperfections of the constraints. Errors of screws. Parallax error.

9. ISOLATION OF APPARATUS FROM DISTURBING INFLUENCES (Page 146)

Effect of disturbances on instruments. Means for reducing sensitiveness to disturbances. Isolating apparatus from mechanical disturbances. The Julius suspension. Millier's mounting. Haringx antivibration mounting. Methods of employing special properties of materials. Temperature variation.

10. DAMPING (Page 171)

Theoretical considerations. Best conditions for damping. Methods of applying damping forces.

11. TESTS FOR STRAIGHTNESS, FLATNESS AND SQUARENESS (Page 179)

Inclination of the surface. Light beam as straightness gauge. Dis- placement from material reference surface. Optically worked glass reference surface (interference method). Liquid reference surface. Standard reference surfaces. Tests for squareness. squareness tests for two flat surfaces, testing two rectilinear motions for squareness.

12. GLASS (Page 192)

Types of glass: window or sheet glass, plate glass, safety glass, fibre glass, chemical glass, optical glass. Optical plastics. Transmission and reflection. Absorption. Detection of defects in glass. Physical properties of glass: density, strength, hardness, elasticity, coefficient of expansion, specific heat, thermal conductivity, thermal endurance, electrical properties.

13. NATURAL AND SYNTHETIC OPTICAL CRYSTALS (Page 233)

Refractive indices of crystalline materials. Instruments.

14. THE WORKING OF GLASS (Page 248)

Cutting, sawing and drilling. Abrasives for glass working: grinding sands, emeries, carborundum, pure alumina (corundum), diamond powder, pumice stone, roughing, trueing and smoothing. Polishing powders: rouge, cerium oxide, white tripoli, putty powder. Trueing tools. Polishers. Making a polisher. Centring and edging. Cementing of glass parts. Cementing of glass to metals. The production of graticules.

15. LENSES, MIRRORS AND PRISMS (Page 270)

General remarks. Thin lenses. Combinations of leases. Spherical aberration. Coma. Astigmatism. Curvature. Distortion. Chromatic aberration. Stops, diaphragms and pupils. Magnifiers. Eye-pieces. Telescope objectives. Microscope objectives. Reflecting microscope objectives. Camera lenses. Condense:rs, Cylindrical lenses. Aplanatic systems: (i) ellipse, (ii) hyperbola, (iii) parabola, (iv) sphere. Lens-rnirror systems. Prisms. Specification of optical parts: plane mirrors, glass windows and filters, prisms, lenses.

16. OPTICAL INSTRUMENTS (Page 346)

The eye. Colour of light. Colour rendering. Defects of the eye. Telescopes. Microscopes. Projectors. Stereoscopic projection.

17. RADIATION AND PHOTOMETRY (Page 377)

Radiation. Thermal radiation. Laws of thermal radiation. Colour temperature. Sources of infra-red radiation. Radiation measurement. Photo-conductive devices. Photo-emissive cells. Photo-multipliers. Photo-voltaic cells. Transistors. Relative sensitivity of detector with any radiator. Ultimate sensitivity of radiation detectors. Photometry. Photometry of optical instalments. Photometric instruments. Some atomic and molecular constants.

18. PHOTOGRAPHY IN RESEARCH (Page 418)

The emulsion. Characteristic curve. Colour film. Exposure. Methods of obtaining increased speed. Grain. Resolution. Processing. Light sources. Exposure meters. Filters. Shutters. Lenses. Cameras. Infra-red and ultra-violet photography. Applications.


[Scanned image of Page xvi]

19. CORROSION IN INSTRUMENTS AND ITS PREVENTION (Page 469)

The general problem. Reduction by improving local conditions. Use of inhibitors in aqueous solution. Yapour-phase inhibitors. Use of suitable materials: bimetallic corrosion, corrosive chemicals. Protection by means of paints, lacquers and enamels. Epoxide resins for finishes. Silicone tinishes. Anti-corrosive finishes for metals (other than paints): zinc, cadmium, nickel, chromium. Various processes for protecting iron and steel. Chemical polishing of steel. Oxide coatings on aluminium and its alloys. Magnesium and its alloys. Polyethylene protective coatings on metals.

Appendix

I. COMPUTATION OF A CORRECTOR PLATE FOR A SCHMIDT CAMERA (Page 491)

II. NOTES ON RAY-TRACING (Page 495)

III. ANGULAR MEASUREMENT (Page 499)

IV. NUCLEAR RADIATION, PROTECTION AND STABILIZED GLASS (Page 501)

V. TABLE FOR USE WITH SAYCE RESOLUTION CHART (Page 504)

INDEX (Page 505)


[Scanned image of Page 1]

CHAPTER 1

GENERAL CONSIDERATIONS

RECENT years have seen a great extension in the use of physical methods in widely differing fields. In all branches of industry, in medical and biological research and in the defence services such methods are used, while many who received their first training as chemists find themselves using the tools of the physicist during the greater part of their working time. The various needs of such workers are partly met by the output of the scientific instrument firms, but new fields of research demand new methods, and much routine test equipment is so specialised that it must be designed for a particular purpose. Some instrument manufacturers undertake the design and construction of special apparatus and in certain classes of work this is undoubtedly the best solution. It is, however, not always satis- factory, unless there is very close co-operation. In every research establishment, a considerable amount of equipment is made by the workshop, usually to the design or instructions of the research worker. It is chiefly to meet the needs of such cases that this book has been written, though it is hoped that it may be of use to the professional instrument designer as well. Apparatus for teaching purposes in universities and technical colleges is often of poor design, and not always suited to its purpose. In this field, too, the apprecia- tion of the principles of good design are important.

Good design will take into account the imperfections of current workshop practice and the limitations imposed by the properties of the materials available. For this reason, we have put these two sub- jects first and have tried to present a picture of what can be expected of a good workshop, and how design can keep the inevitable errors of performance within acceptable limits. The design of many com- mercial instruments is capable of considerable improvement in this respect, though the work of the best firms is above reproach. The subject owes much to the early work of Kelvin, Clerk Maxwell and Darwin, but has been greatly extended and ably expounded by the late Professor A. F. C. Pollard, who died while the first edition of this book was being written.


[Scanned image of Page 2]

Since the eye is the organ chiefly used in accurate perception, the majority of instruments are made for visual observations. Accord- ingly, we have considered the properties and manufacture of optical components as well as the properties of the eye. In many instruments the optical parts may play only a subsidiary rble (often to provide an enlarged image for observation) but are nevertheless very im- portant.

World War II brought home to many academic scientists the importance of the human observer and his relation to the instruments he used. The services rightly insisted that an uncomfortable observer was an inefficient observer, and much attention was paid to comfort. Faulty observation in the laboratory is not deadly as, for instance, in the cockpit of a night fighter plane, but it should be avoided if possible, and instruments should not cause strain or fatigue. It is, however, difficult to reach this ideal at the first attempt, and usually re-design is needed to achieve the best results.

When the principles of sound design are understood, a good deal of work can be done on paper with the assurance that the instrument will function properly when made. Many instances arise, however, when it is impossible to visualise the arrangement and forecast how it will work. This is often the case when a mechanism depends on the action of springs, for instance. In such cases it often saves time if a rough model of such a part is made. Sometimes a " space model " of a part is useful. This is a model, usually made in wood, having the external dimensions of the actual instrument which it represents, but not capable of working. It is useful when the part has to be fitted in some larger assembly.

Optical arrangements are often set up in rough form, using simple components such as spectacle lenses, before the mechanical parts are designed. It is often found, contrary to expectation, that the mechanical parts of an optical instrument are the most difficult to design and make satisfactorily.

Opinions differ as to the extent to which apparatus constructed in the laboratory should be of a makeshift character when it is only to be used for a short time. If the apparatus is made with the least possible expenditure of work, it is true that workshop time may be saved, but a great deal of time may be wasted later by the experi- menter who has to try to make defective apparatus work. It usually pays to have research apparatus soundly constructed, and this is true of the smaller parts of research equipment such as mountings, stands, adjustable holders, etc.. as well as of the larger instruments. At the same time, it will be realised that nothing is gained by a super- the finish. and the condition of rnuch of the material surfaces used in research apparatus is of no importance whatever. This is hardly the case with apparatus used in teaching, for it seems that in many cases students produce better work if they feel that they are using good instruments. Elementary students are only able to judge the per- fbrniance of an instrument to a limited extent, and appearances count for something. For this reason, some attention may be given to finish as well as to function in apparatus for teaching. It is, however, useful to have apparatus in which the difference can be seen between those parts which require accuracy in manufacture and those which do not, provided that the difference is made clear.


[Scanned image of Page 4]

Chapter 2: THE ACCURACY ATTAINABLE IN MACHINING OPERATIONS

Nominal size, tolerance, limits, allowance


[Scanned image of Page 6]

Fig. 2.1: chief parts of intrument maker's lathe. The drive for the spindle at the left hand side is not shown. Work is held in a 3-jaw check

Fig. 2.2: Work supported between centres, driven by dog


[Scanned image of Page 8]

Limits of accuracy to be expected in turning

Plain milling


[Scanned image of Page 10]

Figure 2.3.: Chief parts of plain miller, showing flat face being milled on work. Motion is in direction OZ for this operation.

Surface grinding.


[Scanned image of Page 12]

Fig. 2.4: Essentials of a surface grinder

Centre grinding

Lapping


[Scanned image of Page 14]

Spinning

Location of holes with respect to other holes and to edges and surfaces


[Scanned image of Page 16]

Table 2.1: Accuracy of Holes

References

General References


Chapter 3: PROPERTIES OF MATERIALS USED FOR GENERAL CONSTRUCTION OF INSTRUMENTS

Wood


[Scanned image of Page 18]

Pine

Mahogany

Teak

Iroko

Plywood

Metals


[Scanned image of Page 20]

Wrought iron

Mild Steel

Case Hardening

Hard or carbon steel


[Scanned image of Page 22]

Table 3.1: Tempering of Carbon Steel

Grades of Carbon Steel

Stabilisation

Alloy steels


[Scanned image of Page 24]

Cast Iron

Grey cast iron

White cast iron

Nodular or spherulitic graphite cast iron

Internal damping

Stainless Steel and Iron


[Scanned image of Page 26]

Stainless cutlery steel

Austenite steels


[Scanned image of Page 28]

Iron - Nickel alloys - "Invar"

Copper Alloys

Cartridge brass

Muntz metal


[Scanned image of Page 30]

Turning brass

Table 3.2: Properties of Metals for Construction

Clock brass

Admiralty gunmetal


[Scanned image of Page 32]

Porous bronze

Aluminium and Aluminius Alloys

Aluminium

Aluminium alloys

Duralumin

Y-alloy

Hiduminium R.R. 50.


[Scanned image of Page 34]

D.T.D. 424

General remarks on the use of light alloys

Corrosion-resistant metals (non-ferrous)


[Scanned image of Page 36]

Table 3.3: Corrossion Resistance of Some Metals

Plastic Materials


[Scanned image of Page 38]

Phenol formaldehyde resin

Polymethyl methacrylate


[Scanned image of Page 40]

Polystyrene


[Scanned image of Page 42]

Polyethylene

Table 3.4: Properties of some plastics


[Scanned image of Page 44]

Polytetraflourethylene (P.T.F.E.)


[Scanned image of Page 46]

Polyvinyl chloride


[Scanned image of Page 48]

Silicon elastomer

Materials for Springs

Elastic properties

Fig. 3.1: Typical endurance limit curves for Mallory 73 Beryllium Copper in reversed bending. Arrow heads indicate unbroken test pieces. (Mallory Metallurgical Products Ltd.)


[Scanned image of Page 50]

Fig. 3.2: Tensile stress-strain curves for spring materials in strip form. (Mallory Metallurgical Products Ltd.)

Steel

Phosphor bronze

Fig. 3.3: Torsional stress-strain curves for spring materials in the form of 0.10 in. diameter wire. (Mallory Metallurgical Products Ltd.)

Beryllium copper


[Scanned image of Page 52]

Table 3.5: Heat Treatment of Mallory 73 Beryllium Copper

Fig. 3.4: Elastic properties of fused silica fibres (Reinkober) : (a) Modulus of elasticity (old fibres); (b) Modulus of elasticity (etched fibres); (c) Modulus of torsion (old fibres); (d) Modulus of torsion (etched fibres)

Fused silica


[Scanned image of Page 54]

Table 3.6: Strength of Silica Fibres

References


[Scanned image of Page 56]

Chapter 4: CASTING AND JOINING OF METALS

Casting

Fig. 4.1: (a) Pattern from which a casting is to be made, and (b) Moulding box filled with sand, showing mould formed by removal of pattern.

Fig 4.2: Pattern and core required to make a casting with a hold right through


[Scanned image of Page 58]

Jointing

Soldering and brazing

Welding

Electric Welding


[Scanned image of Page 60]

Frame welding

Flame Cutting

General observations on welding

Resin-Bonded Construction


[Scanned image of Page 62]

Araldite Type 1.

Table 4.1

Cold-setting Araldite


[Scanned image of Page 64]

Table 4.2: Dimensions of Small Rivets (See Fig. 4.3) Data from British Specification 641, 1935)

Jointing by mechanical means

Rivets

Fig 4.3: Various rivets. The relative dimensions of rivets according to B.S.S. 641, 1935, are given in Table 4.2.

Screws


[Scanned image of Page 66]

Fig. 4.4.: Types of screw heads and plain nuts

Fig. 4.5.: Use of taper pins to secure accurate location of a removable part. The counterbored holes are used wen screw heads must not project.

Fig. 4.6.: Hexagon socketed cap screw and wrench

Fig. 4.7.: Showing the use of socketed cap screws in a situation inaccessible to a screwdriver or spanner.


[Scanned image of Page 68]

Locking of screws and nuts

Fig. 4.8.: Methods of locking screws and nuts. The Simmonds nut is self-locking.

Relative advantages of cast and built-up work


[Scanned image of Page 70]

References


Chapter 5: PREPARATION OF DRAWINGS

Material for drawing


[Scanned image of Page 72]

Assembly and detail drawings

Fig. 5.1.: Relative positions of various views of an object using British standard projection (B.S. 308: 1943)

Method of projection

Fig. 5.2.: Relative positions of views in American projection. (B.S. 308: 1943)

Types of line

Scale

Sections


[Scanned image of Page 74]

Screw threads

Types of Lines

Fig 5.3: Types of line. (B.S. 308: 1943)

Fig 5.4: Section in one plane not on centre lines. (B.S. 308: 1943)

Fig 5.5: Section in one plane along centre line. (B.S. 308: 1943)

Fig 5.6: Section in two planes. (B.S. 308: 1943)

Fig 5.7: Superimposed cross sections. (B.S. 308: 1943)

Fig 5.8: Cross section places to one side (B.S. 308: 1943)

Fig 5.9

Fig 5.10

Fig 5.11.

Fig 5.12.

Fig 5.13.

Fig. 5.9-5.13: Conventional representation of screw threads. (B.S. 308: 1943)


[Scanned image of Page 76]

Dimensions and tolerances

Fig 5.14: Method of indicating dimensions and tolerances

Additional instructions

Fig 5.15: Conventional "breaks" (B.S. 308: 1943)

Reproduction of drawings


[Scanned image of Page 78]

Reference


Chapter 6: CONSTRAINED MOTION AND CONSTRAINTS

Kinematic or Geometric Design

Degrees of freedom


[Scanned image of Page 80]

Fig 6.1: Kinematic slide allowing movement of a carriage in a straight line.


[Scanned image of Page 82]

Fig 6.2: Kinematic design employing cylindrical surfaces as guides. Such surfaces can be accurately made.

Fig 6.3: Kinematic slide. The spheres are fixed to the carriage.

Fig 6.4: Carriage of Wickman gauge, giving very free motion by the use of rolling spheres D and E.


[Scanned image of Page 84]

Fig 6.5: Symmetrically opening slit for optical instruments. Rolling motion of spheres is employed. The figure is drawn in American projection; the side view shows the end plates removed.

Fig 6.6: Simple kinematic arrangement giving rotation about a vertical axis.


[Scanned image of Page 86]

Fig 6.7: Micrometer movement for rotating a vertical shaft, using kinematic principles.

Fig 6.8: Arrangement for rotating carriage round an arc of large radius.

Fig 6.9: Rotatory motion using rolling spheres.


[Scanned image of Page 88]

Body without freedom

Fig 6.10: Accurate locatino of removable part obtained with vee-grooves for ball-ended feet.

Fig 6.11: Adjustable mirror mount or levelling table.

General remarks on geometric design


[Scanned image of Page 90]

The accuracy of performance of a geometrically constrained mechanism

Modifications to geometric design


[Scanned image of Page 92]

Fig 6.12: Semi-kinematic element, with bearing surfaces of appreciable area.


[Scanned image of Page 94]

Fig 6.13: Semi-kinematic slide of Sartorius microtome

Constrained motion employing elastic deformation

Fig 6.14: Strip hinge, giving rotation about a fixed axis and using elastic deformation

The Cross-Spring Pivot


[Scanned image of Page 96]


[Scanned image of Page 98]

Effect of large deflections

Strips giving parallel motion


[Scanned image of Page 100]

Fig. 6.15.: Stiffness of a symmetrical cross-spring pivot consisting of two pairs of spring strips intersecting at 90 deg. at their mid-points. Width of each spring = 1/4 in. (Nickols and Wunsch(10).) (Crown Copyright Reserved.)

Fig. 6.16.: Shift of axis of rotation of symmetrical cross-spring pivot consisting of two pairs of spring strips intersecting at 90 deg. at their mid-points. (Nickols and Wunsch(10).) (Crown Copyright Reserved.)


[Scanned image of Page 104]

Fig 6.17: Use of spring strips to give motion in a straight line (for small displacements)

Springs and clamps

Fig 6.18: Good (a) and bad (b) forms of springs for holding moving parts in contact with their guides.

Fig 6.19: Spring washer for preventing backlash in screw and nut

Fig 6.20: Spring-loaded plunger for adjusting screw

Clamps

Fig 6.21: Self-adjusting foot for clamping screw.


[Scanned image of Page 102]

Fig 6.22: Retort stand boss with springs to allow regulation of clamping force

Fig 6.23: Clamping arrangement for plane mirror (Hilger spectrometer)

Fig 6.24: Clamping of plane mirror in Perkin-Elmer spectrometer


[Scanned image of Page 108]

References


Chapter 7: THE MAGNIFICATION OF SMALL DISPLACEMENTS

Mechanical Methods


[Scanned image of Page 110]

Lever Magnification

Fig 7.1: Lever using cross-spring pivot to give rotation about a fixed point and hence to magnify plunger movement by a constant factor.

Rolling cylinder and related methods


[Scanned image of Page 112]

Fig 7.2: Differential roller mechanism

Parallel deformable strips

Fig 7.3: Magnification of movement by use of deformable perallel strips

Ratchet and toothed wheels. Dial gauges

Fig 7.4: Dial gauge (Mercer). A similar gauge is shown in use in Fig 11.7.


[Scanned image of Page 114]

Liquid levels

Fig 7.5: Principle of liquid level.

Conditions affecting liquid levels


[Scanned image of Page 116]

Mounting of levels

Liquid levels for magnifying small movements

Magnification by Optical Methods

Fig 7.6: Fiduciary mark and scale, as used in Watts level.


[Scanned image of Page 118]

Magnification by optical lever

Fig 7.7: Optical lever for high magnification (Dye)

Observation of angular movement of light beams

Fig 7.8: Lamp and scale to read deflections of optical lever


[Scanned image of Page 120]

Fig 7.9: Contours of geometrical and of diffraction images of a narrow wire


[Scanned image of Page 122]

Fig 7.10: Observation of mirror deflection by means of telescope and scale.

The Auto-collimator

Fig 7.11: Auto-collimating telescope for observing mirror deflection. If no condensor is used between lamp and graticule, a frosted bulb should be used to illuminate the required field of view.


[Scanned image of Page 124]

Moire fringes

Fig 7.12: Moire fringes for superposted gratings


[Scanned image of Page 126]

Interference methods

Fig 7.13: Arrangements for viewing interference fringes formed in thin air film between two semi-reflecting surfaces.


[Scanned image of Page 128]

Fig 7.14: Arrangement using parallel light to produce interference fringes between well-separated surfaces.

The thermal relay

Fig 7.15: Thermo-couple (Moll and Burger for thermal relay)


[Scanned image of Page 130]

Photo-electric relay

Fig 7.16: Arrangement of optical parts in photo-voltaic relay.

Fig 7.17: Grids for more sensitive photo-voltaic relay.


[Scanned image of Page 132]

Fig 7.18: Photo-voltaic arrangement with feed-back (Preston) (optical arrangement not shown, but similar to Fig. 7.16)

Electrical Methods

References


[Scanned image of Page 134]

Chapter 8: SENSITIVITY AND ERRORS OF INSTRUMENTS

Sensitivity of instruments


[Scanned image of Page 136]

Fig 8.1: Suspended system of Moll galvanometer

Errors


[Scanned image of Page 138]

Systematic Errors

Errors due to imperfections of the constraints

Fig 8.2: Illustrating errors introduced by lack of straighness of constraints.


[Scanned image of Page 140]

Errors of screws

Fig: 8.3: Plain thrust bearing in which the faces are not perpendicular to the axis of rotation.


[Scanned image of Page 142]

Fig 8.4: Ball ended strut for coupling two colinear movements

Parallax error.


[Scanned image of Page 144]

Fig 8.5: Use of mirror to avoid parallaz error.

Fig 8.6: Arrangement for projecting virtual image of illuminated pinhold on object to be measured, so avoiding parallaz errors.

References


[Scanned image of Page 146]

Chapter 9: ISOLATION OF APPARATUS FROM DISTURBING INFLUENCES

Effect of disturbances on instruments

Fig 9.1: Rigid body suspended by single fibre


[Scanned image of Page 148]

Fig 9/2: Rigid body held between stretched fibres

Means for reducing sensitiveness to disturbance


[Scanned image of Page 150]

Isolating apparatus from mechanical disturbances

The Julius suspension

Fig 9.3: Julius anti-vibration suspension


[Scanned image of Page 152]

Table 9.1: Damping of Pendulum

Muller's mounting


[Scanned image of Page 154]

Fig 9.4: Muller's anti-vibrational support

Haringz anti-vibration mounting


[Scanned image of Page 156]

Fig 9.5: Diagram (a) and frequency characteristic (b) of an undamped, vibration-free system.

Fig 9.6: Diagram (a) and frequency characteristic (b) of a vibration-free system with "relative" damping.

Fig 9.7: Diagram (a) and frequency characteristic (b) of a vibration-free system with "absolute" damping.


[Scanned image of Page 158]

Fig 9.8: Vibration-free system with auxiliary mass M.


[Scanned image of Page 160]

Fig 9.9: Frequency characteristic of the system shown in Fig. 9.8 for the two extremes of damping with k= infinity and k=0.

Fig 9.10: Frequency characteristic of an undamped system (curve 1), a system with auxiliary mass and "optimum" parameters chosen for u = 0.5 (curve 2) and a system with relative damping (curve 3). It is assumed that the total mass and also the rigidity of the spring c is the same in all three systems. Further, for curve 3 the damping was the same in all three systems. Further, for curves 3 the damping was so chosen that the maximum amplitude ratio is the same as in case 2.

Fig 9.11: The decay of the free vibrations after a given initial displacement for a system according to Gif. 9.8a and u = 0.5 and the optimum parameters p = 0.5 and q = 0.62.


[Scanned image of Page 162]

Fig 9.12: Three different arrangements for making an apparatus vibration-free where multi-dimensional disturbing vibrations exist. The mounting are all symmetrical with respect to two perpendicular vertical planes.

Fig 9.13: Model of vibration-free mounting with auxiliary mass.

Fig 9.14: Example of a vibration-free mounting. The dimensions are 60 x 60 x 15 cm. ; its weight is 110 kg. The two plates a and b together form the main mass. They are connected by twelve rods c. The main mass rests upon four helical sprigs d. The auxiliary mass e is coupled to themain mass by eight springs f. The cup g is one of four damping elements.

Methods employing special properties of materials.


[Scanned image of Page 164]

Fig 9.15: "Silentbloc" anti-vibration support, using rubber (shown black) bonded to metal.

Fig 9.16: Anti-vibration support using inflated rubber tyres (Gehrcke and Voight)

Temperature variation


[Scanned image of Page 166]


[Scanned image of Page 168]

Fig 7.19: Toluene thermostat with large surface for air temperature control


[Scanned image of Page 170]

General Reference

References

Chapter 10: DAMPING


[Scanned image of Page 172]

Theoretical considerations

Fig 10.1: Damped harmonic motion


[Scanned image of Page 174]

Best conditions for damping

Fig 10.2: Damped harmonic motion in neighbourhood at first minimum (on large scale). n=1/2

Methods of applying damping forces


[Scanned image of Page 176]

Fig 10.3: Variation in viscosity with temperature for some fluids suitable for damping. The full lines show curves for silicones, the broken curves refer to hydrocarbon oils. (Dow Corning Corporation)

Fig 10.4: Oil damping for the movement of a pen recorder.


[Scanned image of Page 178]

Fig 10.5: Air damping arrangement on a chemical balance

Reference


Chapter 11: TESTS FOR STRAIGHTNESS, FLATNESS AND SQUARENESS

Inclination of the surface


[Scanned image of Page 180]

Fig 11.1: Use of optical lever for measuring flatness of surface


[Scanned image of Page 182]

Fig 11.2: Curvature of surface revealed by astimatism

Light beam as straightness gauge

Displacement from material reference surface

Optically worked glass reference surface (interference method)


[Scanned image of Page 184]

Fig 11.3: Interference bands formed between flat and test object.

Liquid reference surface

Fig 11.4: Method of using liquid reference surface for checking flatness of plate. The micrometer is electrically insulated from the mercury cup.


[Scanned image of Page 186]

Standard reference surfaces

Fig 11.5: Checking surface plate against straight-edge by means of dial gauge.

Tests for Squareness

Squareness tests for two flat surfaces


[Scanned image of Page 188]

Fig 11.6: Standard square (to be replaced by test piece) on surface plate with dial gauge on kinematic slide.

Fig 11.7: Checking a square whose opposite sides are known to be accurately parallel, be reversal through 180 deg.


[Scanned image of Page 190]

Fig 11.8: Use of auto-collimating telescope in test for squareness.

Testing two rectilinear motions for squareness

References


[Scanned image of Page 469]

Chapter 19: CORROSION IN INSTRUMENTS AND ITS PREVENTION

The general problem


[Scanned image of Page 470]

Reduction by improving local conditions


[Scanned image of Page 472]

Use of inhibitors in aqueous solution

Vapour-phase inhibitors


[Scanned image of Page 474]

Table 19.1: Saturation Vapour Pressures (in mm. Hg)

Use of suitable materials

Bimetallic Corrosion


[Scanned image of Page 476]

Table 19.2: Degree of Corrosion at Bimetallic Contacts

Table 19.2: Notes


[Scanned image of Page 478]

Corrosive chemicals

Protection by means of paints, lacquers and enamels


[Scanned image of Page 480]

Epoxide resins for finishes

Epoxide Ester REsins

Epoxide Resins Cross-Linked with Phenolic or Amino Resins

Epoxide Resins CRoss-LInked with Amines


[Scanned image of Page 482]

Silicon finishes

Anti-corrosive finishes for metals (other than paints)


[Scanned image of Page 484]

Metallic Coatings

Zinc

Cadmium

Nickel

Chromium


[Scanned image of Page 486]

Various processes for protecting iron and steel

Chemical polishing of steel


[Scanned image of Page 488]

Oxide coatings on aluminium and its alloys

Magnesium and its alloys

Polyethylene protective coatings on metals


[Scanned image of Page 490]

References



[Scanned image of Page 505]

INDEX

ABERRATIONS


Abrasives for glass, 253--7
Absorption of light, 21 8--24 Accuracy Acuity, visual, 357
Adcock and Shipley machine, 254
Aero Research Ltd., 265, 479
Afrormosia, 18
Air damping, 177-8
Alignment of lathe spindle, 7
Albright and Wilson Ltd., 485
Allen screw, 67
Allowance, 5
Allsop, G., 133
Aloxite, 257
Alumina for grinding, 236-7
Aluminium alloys, 32- 35 Aluminium oxide (sapphire, corundum), refractive index, 236, 242,247
Aluminium soldering, 32-33
American Optical Co., 247
American Standard exposure index,422, 424
Ammonium aluminium sulphate, refractive index, 242
Ammonium dihydrogen phosphate, 235 AngleDekhor, 124, 189, 190, 365
Angular measure, 499-500
Angular movement, observation of, I 19-25
Anodic oxidation, of aluminium, 488-9
Anti-corrosive finishes
Anti-shake washer, 68
Anti-vibration mounting
Aplanatic system, 282, 314 18
Applications of photography, 467
Araldite, 62-64, 265-6
Arsenic trisulphide glass, 237-8 Aspheric surfaces, 315
Assembly drawing, 72
Astigmatism, 282 Astronomical telescope, 360
Atomic and Molecular Constants, 415
Austenitic steel, 27-28
Auto-collimator (telescope), 123-5, 178-89, 190

BACK CENTRE, USC Of in turning, 7-8
Back-lash, prevention of, 104
Bakelite, 38
Balancing of galvanometer, 149
Balls, accuracy of, 85
Barium fluoride, 235

Barnes, R. B., 136
Barr and Stroud Ltd., 214, 215, 237, 240, 244, 449, 463, 471
Bausch and Lomb, 200, 203
Beam splitters, 212, 214, 440
Beatt, A. A. G., 426
Beck, R. and J. Ltd., 302
Bent telescope, 364
Beryllium copper, 51-53 Bimetallic corrosion, 475-8
Binocular magnifier, 291
Binocular microscope, 366
Black body radiation, 377, 379-82
Black oxide coating for steel, 486-7
Blooming of lenses, 211-12, 306, 461
Blue-print, 77
Bolometer, 384-5, 386, 413
Bostick cement, 266
Bourne, E. K., 445
Bouwers, A., 303, 304
Bowen, E. J., 454
Boxwood, 19
Boys, C. V., 55
Brass


[Scanned image of Page 506]

Brazeing, 58-59
Brewster's law, 211
Briggs, H. B., 246
Brightness (Luminance)

Brightness and illumination (table), 398
British Drug Houses, 453
British Standard exposure index, 422, 424
Bronze, porous, 32
Brookes, J. C., 116
Brownian movement, 135-7
Browning process, 487
Brush Development Company, 235
Built-up edge, 8
Burch, C. R., 301, 302, 303
Burger, H. C., 129, 135

CADMIUM COATINGS, 484
Cadmium fluoride, refractive index, 242
Cadmium sulphide cell, 386
Caesium bromide, 235

Caesium iodide, refractive index, 236, 247
Calcium fluoride (fluorite), 234 Calespar (Iceland spar), refractive Calorex glass, 132
Camera lenses, 304-11 Cameras, 461-3, 466 Canada balsam, 263-5
Candle-power, 397
Carbon are, 350, 384
Carbon steel, 21
Carborundum, 256
Carborundum Company, 257
Cartridge brass, 29
Case-hardening, 21
Cast iron, 24-25 Casting, 56-58
Casting, advantages of, 69-70
Cellulose caprate cement, 265
Cellulose finishes, 479
Cements for glass (optical), 263-7
Centre grinding, 13
Centres, turning between, 6
Centring lenses, 263
Cerium oxide, 259
Cerroseal, 266-7
Chance Bros.Ltd., 199,203,220,222,449
Characteristic curve, photographic 420, 421, 423 '
Chasmar, R. P., 396, 413
Chemical polishing of steel, 487-8
Chromatic aberration, 286-7, 459-60
Chromaticity coordinates, 352-3
Chromium coatings, 480
Chuck, magnetic, 12
Ciba Ltd., 61
C.I.E. diagram, 354
Cine camera, 462, 463
Clamping screw, LOG
Clamps, 105-7
Clerk Maxwell, 79, 81
Cobb, 436
Collatz, L., 159
Colour, 351-6 Coma, 281, 283
Combination of lenses, 277-8
Comite Internationale de l'Eclairage, 348, 351 Comite Internationale des Poids et Mesures, 348
Compensation for temperature change, 166, 167
Condensers, optical, 311-14, 367-71
Conductivity, thermal Constrained motion, 79-107
Contraction rule, 57
Cooke telescope objective, 296
Copper alloys, 29-32
Copper Developarrent Association, 29
Core, in casting, 57
Corex glass, 222
Corning glassworks, 222
Cornu prism, 233
Corrosion in insitruments, 469-90
Corrosion resistant metals, 35
Corrosive chemicals, 478
Corundum (alumina), 256
Coupled vibrations, 155-61
Critical damping, 171
Critical humidity, in corrosion, 471
Crookes glass, 21La
Cross-spring pivot, 95--99
Crystal growing, 237-9
Crystals, optical, 233-47
Crystals, refractive indices, 201, 236, 241-7
Curvature of image, 284-5, 291
Cutters, milling, 10
Cylindrical lenses, 314

DAMPED HARMONIC MOTION, 172-4
Damping

Dark adaptation of eye, 348
Darwin, Sir Horace, 79, 143
Debrie, A., 438, 463
Deep pictures, 375
Defects of glass, detection of, 224--9
Degrees of freedom, 79-82
Density, optical, 206-7, 218-24 Deve, C., 265, 266, 267
Dial gauges, 113 Dial sight, 365
Diamond Diaphragms in optical systems, 288-9
Dickson, J. Home, 229, 231, 449
Dielectric films, 212-16
Diffraction image of wire, 121
Dimensions and tolerances, 76-77
DIN sensitometry, 421, 423
Dioptre, 272
Dispersion, 198-206
Dispersive power, 198
Distortion of image, 285
Distribution coefficient, 351-2
Disturbance, effect of mechanical, 146-9 Dove prism, 321, 344, 364
Dow-Corning Corporation, 479, 483
Dow processes, 489
Dowels, use of, 66
Drawings, 71-78
DTD-424, 34
du Bois, H. E. J. G., 146
Dumet, 29
du Pont de Nemours, 45
Dudley, 442
Duralumin, 33
Dye, D. W., 118
Dye-line print, 77
Dyson, J., 182, 367

ECLAIR COMPANY, 462
Edging lenses, 263
Elastic deformation, 95-102
Elasticity

Electrical methods of magnification, 133
Electromagnetic damping, 177
Electromagnetic spectrum, 378
Elinvar, 29
Ellipsoid, 315-16
Elutriation of emery, 255-6
Emery, 255-6
E.M.I. Electronics Ltd., 390
Emulsion, photographic, 4 18
Emulsion speeds, 421-7, 464-5
Enamels, 478-83
Energy distribution of illuminants, 351
Entrance pupil, 288
Epikote (Epon) rcsins, 265
Episcope, 410
Epoxide lacquers, 479-82
Epoxy resins, 61-64, 216
Epps, T. D., 129
Equivalent foot-candle, 398, 403
Erecting systems, 361-2
Errors of instruments, 137-45
Evershed-Vignoles recorder, 177
Exit pupil, 288
Expansion, thermal Exposure meter, 445-7
Exposure, photographic, 426, 428
Eye, 346-50
Eye clearance, 294
Eye, defects of, 356-7
Eyepieces, 290-5

FABRY-PEROT INTERFEROMETER, 129
Fastax high speed camera, 463
Fatigue in photo-cells, 132
Fechner fraction, 349
Fechner's law, 349
Fernico, 29
Fibre glass, 196-7
Fibres, fused silica, 53
Film speeds, 418, 421-7, 464--5
Films, non-reflecting, 211-12, 306, 461
Filters for mercury lines, 453, 454
Filters for photography, 447-54
Filters, interference, 214-18
Filters, testing, 227
Firth-Vickers Ltd., 30
Fizeau, H., 126
Flame cutting and welding, 60
Flatness

  • interference test for, 183-4
  • optical test for, 181-2
  • testing for, 179-87 Flats, testing of, 227
    Flats, optical, specification for, 324-5
    Fluorite, refractive index of, 201, 236, 242-3


    [Scanned image of Page 508]

    Flux, luminous, 397
    F-nurnber, 304, 309-11
    Focal length of lenses, 272-8
    Foot-candle, 398, 401
    Foot-lambert, 398, 403
    Forrester, G. O., 143
    Foucault knife-edge test, 358
    Fraunhofer telescope objective, 296
    Fused quartz, 53-55

    GARNET, REFRACTIVE INDEX OF, 242
    Gauss telescope objective, 295-6
    Gehrcke, E., 164-5
    General American Transportation Corporation, 485
    General Electric Co. Ltd., 233, 247
    Geometric design, 79-94
    Germanium, 237, 246
    Glass,
    Globar, 383
    Golay cell, 387, 397
    Grain, photographic, 429-30
    Graticule, 117
    Graticules, production of, 267-8
    Gratings for Moire fringes, 125-6
    Griffiths, H. D., 384
    Grinding Guillaume, 28-29
    Gunmetal, 31

    HANOVIA CHEMICAL COMPANY, 233, 247
    Hardening (case-), 2 1
    Hardening of steel, 21-22
    Hardness

    Hardy, A. C., 282
    Haringx, J. A., 96, 98, 99, 155, 162, 163
    Harrold, B. P., 190
    Harshaw Chemical Company, 235, 245,247
    Hawkins, 320
    Henney, 442
    Heraeus Quartzschmelze GMBH, 234,247
    Herapathite, 223
    Hettner, 243
    Hexagon socketted cap screw, 67
    Hiduminium, 33-34 High Duty Alloys, Ltd., 33
    High resolution plates, 431
    High speed camera, 457-8, 463, 466
    High speed steel, 23-24
    Hilger and Watts, Ltd., 115, 124, 189, 235, 265, 365, 413, 414
    Hilger spectrometer, 107
    Hohls, H. 17., 241
    Hole, slot and plane, 88
    Holes, location of, 15
    Hopkin and Williams Ltd., 259, 265, 453
    Humidity, relative, effect on corrosion, 470-2
    Hurter & Driffield curve, 420-1
    Huygens eyepiece, 294
    Hyperboloid, 316
    Hysil, 222
    Hysteresis loop in instrument, 138

    ICE, REFRACTIVE INDEX OF, 242
    Ilford Ltd., 223, 427, 440, 449
    Illumination, 398-9
    Imperial Chemical Industries Ltd., 30, 41, 42, 43, 45
    Increased speed of photographic emulsion, 427 8
    Infra-red

    Inhibitors (rust) in aqueous solution, 472 Insert bushes, 67
    Interference Intensity, luminous, 397
    International Critical Tables. 247
    Invar, 28
    Iroko, 19
    Iron-nickel alloys, 28-29
    Iron, wrought, 20
    Ising, G., 135
    Isolation of apparatus

    JENA GLASSES, 203, 222
    Johansson gauges, 14
    Johnsons Ltd., 437
    Johnson and Matthey Ltd., 266
    Jointing, 58-68
    Jones, F. E., 396, 413
    Jones, R. V., 102, 132
    Julius suspension, 151-2
    Julius, W. H., 150

    KANIGEN COATINGS, 86
    Kaye, 352
    Kellner eyepie.ce, 289, 204
    Kelvin, Lord, I
    Kerr cell, 455
    Kinematic design, 79-94
    King's College, London, 302
    Knife-edge test, 358
    Kodak Ltd., 223, 437, 438, 440, 449, 457, 458, 463
    Kodak High Speed camera, 463
    Kovar, 29
    KRS5 and 6, refractive index, 236, 242, 243

    LABY, 352
    Lacquers, 478 -83
    Lambert, definition of, 403
    Lambert's law, 400, 403-4
    Lamp and scale, 119-22
    Lapping, 13
    Lathe turning, 5
    Lazulite, 257
    Lead fluoride, refractive index, 242
    Leisegang, 243
    Lenses

    Lens formulae, 272--80
    Lens-mirror systems, 318-20, 491
    Level, liquid (spirit), 114-7, 179
    Levelling table, 88
    Levers Light alloys, 32-34 Light beam as straightness gauge, 182-3
    Lighthouse lenses, 312-13
    Light sources Limits, 715--77
    Linde Air Products, 235, 247
    Linfoot, 320
    Liquid level, 114-16, 179
    Liquid reference surface, 184-5
    Lines for drawings, 74
    Lister microscope objective, 300
    Lithium fluoride, 234 Lloyd, H., 133
    Location of holes, 15-16
    Location of removeable parts, 88
    Locking screws and nuts, 68-69
    Logarithmic decrement, 173
    Low expansion alloys, 28-20
    Lurnen, 397, 399
    Lunleter, 415
    Lurninance, see Brightness
    Luminosity, 350, 399
    Luminosity curves, 347
    Luminous efficiency, 399 Luminous intensity, 399
    Lummer-Brodhun photometer, 412
    Lux, 398, 401


    [Scanned image of Page 510]

    MACBETH ILLUMINOMETER, 415
    Magnesium oxide, 235

    Magnification Magnifiers, 289-90 Mahogany, 18
    Maksutov, 316, 319, 320
    Malleable castings, 24
    "Mallory 73", 52
    Mallory Metallurgical Products Ltd., 49, 50, 51, 52
    Mangin Mirror, 318-19
    Martin, L. C., 348, 409, 410
    Maxwell's condition in kinematic design, 81
    McFee, R. A., 383
    McLeod, 219, 220
    Mechanical magnification, 109-14
    Meehanite iron for glass-working tools, 260
    Mercer, T., Ltd., 113
    Merton, Sir Thomas, 142
    Merton nut, 126, 142-3
    Metals Meter-candle, 401
    Michelson, A. A., 126
    Micrometer movement, 86
    Microphen developer, 427
    Microscope, 296-304, 366-7 Midland Silicones Ltd., 483
    Mild steel, 20-21 Miller, plain, 10 Milling, 9-11
    Mirror mount, adjustable, 88
    Mirrors, clamping of, 107 Moire fringes, 125-6
    Moisture on glass, elimination of, 215-16
    Mole-Richardson Ltd., 444
    Moll, J. W. H., 129, 135
    Moll galvanometer, 136-7, 148-9
    Moulding box, 56
    Monochromator, 238-241
    Mullard Ltd., 251, 391, 394
    Miller anti-vibration suspension, 152-5
    Muntz metal, 29

    NAILS IN WOOD, 18
    National Bureau of Standards, 203, 268, 309, 397, 436
    National Physical Laboratory, 109, 110, 112, 116, 126, 143, 179, 188, 397
    Negative feed-back, 131
    Nernst filament, 384, 414
    Nickel coatings, 485
    Nickols, L. W., 98, OD, 100, 101
    Night glasses, 408
    Noise, 172
    Nominal size, 5
    Norris, K. P., 304
    North Thames Gas Board, 260
    Norton Grinding Company Ltd., 237
    Numerical aperture (N.A.), 297-8
    Nuts, 66

    OBJECT AND IMAGE DISTANCEs, 276
    Objectives

    Oil damping, 177
    Opacity, 206-7
    Optical flat Optical glass, 197-205 Optical instruments, 346-76
    Photometry of, 405-11 Optical lever, 118 Optical methods of magnification, 117-32
    Optical parts Overshoot, 175
    Oxide films, protective

    PAINTS, 478- 83
    Paraboloid, 316
    Parallax error, 143-5
    Parallel strips, 112
    Parra-Mantois Glassworks, 203
    Partridge, J. H., 231
    Patterns for castings, 57-58
    Pentagonal prism, 321, 342
    Periclase, 237

    Periodic error of screw, 141-2
    Periodic time (effect of damping on), 173
    Periscope system, 363, 365
    Perkin-Elmer spectrometer, 107
    Perrin, F. H., 282
    Perspex, 39-41, 205-6
    Petzval curvature, 291 Pfund, A. H., 131
    Phenol formaldehyde resin, 38 Phoenix glass, 197
    Phosphor bronze, 50 -51 Phot, 398
    Photicity, 442
    Photo-cell, emissive, 387, 390, 391
    Photo-conductive cell, 385-8
    Photo-elasticity, 228-9
    Photo-electric relay, 130-2
    Photographic Photography, 418-67
    Photometric instruments, 411-15
    Photometry, 397-415
    Photomicrography, 466-7
    Photo-multipliers, 392-3
    Photopic vision, 346-7
    Photo-voltaic cells, 393-4
    Physical properties Pilkington Bros. Ltd., 222
    Pinhole photography, 462
    Pitch for polishing, 260
    Planck's law, 380-1
    Plastic materials, 36-49, 205-6 Plywood, 19
    Point contacts, 91-92
    Polarisation of light, 210-12, 223
    Polarised light, reflection of, 211-12
    Polaroid, 223-4
    Polisher, making, 261-2
    Polisher for glass, 260-2
    Polishing powders, 259
    Pollard, A. F. C., 1, 79, 137, 138
    Polyethylene, 42-44 Polyethylene coatings, 489-90
    Polyrnethyl methacrylate, 39-41 Polystyrene, 41-42 Polytetrafluorethylene, 45-47 Polyvinyl chloride, 47-48 Porro prism, 361, 363
    Potassium aluminium sulphate (potash alum) Potassium chloride (sylvine), 235 Potassium bromide, 235 Potassium dihydrogen phosphate, 237 Potassium iodide, refractive index, 201, 236, 242
    Preston, J. S., 131
    Prisms, 321-3 Processing, photographic, 435-40
    Profile microscope, 372
    Profile projection, 370
    Projection, stereoscopic, 373-5
    Projection systems, 369-75
    Projections, standard (in drawing), 73
    Projectors, 367-76
    Protection Protective glasses, 223
    Pumice powder, 257
    Pupils, entrance and exit, 288-9
    Purkinje effect, 348
    Putty powder, 259
    Pyrex glass, 197

    QUARTZ (CRYSTAL), refractive index, 236, 242-3 Quartz fibres, 53-55
    Quartz, fused, 233-4

    RADIATION, 377-82

    Radiography, 61
    Raine, H. C., 206
    Ramsden eyepiece, 289-90, 294
    Rank, D. H., 124
    Rayleigh, Lord, 184, 408
    Ray-tracing, 274, 495-8
    Reciprocity failure, 426, 428
    Reflecting microscope objectives, 301-4
    Reflecting telescope, 360
    Reflection of light, 206-217 Reflector sight, 363
    Reflex copying, 77-78


    [Scanned image of Page 512]

    Refractive index

    Reinkober, O., 53
    Relay Reproduction of drawings, 77-78
    Resin-bonded construction, 51-64 Resolution Reticule, see Graticule
    Retina, sensitivity of, 348--9
    Rigidity of work, need for, 4
    Rivets, 64-65
    Roberts, ]. K., 384
    Rodney, W. S., 244-5
    Rolling, magnification by, 111-12
    Rolls Royce Ltd., 33
    Rolt, F. H., 179
    Ross, 436
    Ross cement, 265
    Rotation about axis, 85- 87, 95--99
    Rouge, 259
    Roughing, 257-8
    Rowland, H. A., 142
    Rubens, H., 146
    Russian Glass classification, 203
    Rutile, 235

    SAGITTAL IMAGE, 283-4
    Salford Electrical Instrument Co. Ltd., 235
    Sands for glass-working, 253
    Santen, v., 146
    Sapphire, 235

    Sartorius microtome, 93-94
    Sayce, L. A., 436, 504
    Scheiner sensitometry system, 421, 423
    Schlesinger, E., 179
    Schlieren observation, 226
    Schmidt optical system, 316, 318, 319, 373, 491-4
    Schott & Gen., 203
    Schwarz thermocouple, 385-6, 414
    Schwarzschild's law, 426
    Scotopic vision, 346-7
    Screens for projection, 372-3
    Screw Searchlight, 411
    Sears, 110
    Secondary spectrum, 286
    Seed in glass, detection of, 224
    Seidel aberrations, 285- 6
    Selenium, 237
    Self-tapping screw, 67
    Selwyn, E. W. H., 309, 436
    Semi-geometric (semi-kinematic) design, 92-94
    Sensitivity Servo Corporation of America, 237
    Shaping machine for glass, 254
    Shell Chemical Corporation, 479
    Shell Chemicals, Ltd., 265, 479
    Shell V.P.I., 473
    Shutters Silentbloc mounting, 162, 164
    Silica, fused see Quartz, fused
    Silicon, refractive index, 246
    Silicone Silver chloride, 235 Silverman, S., 136, 383
    Simmonds nut, 68
    Sine condition, 281
    Sira abrasive, 256-7
    Sira rouge, 259
    Slit, symmetrically opening, 84
    Smith, L. G., 384
    Smith, R., 301
    Smith, R. A., 396, 413
    Smoothing, 257-8
    Sodium aluminium sulphate (sod. alum), refractive index, 242
    Sodium chloride, 235 Sodium fluoride, refractive index, 236, 241-2
    Sodium nitrate, 237 Soldering, 58-59
    Source Specific gravity Specific heat Specification of optical parts, 323-9
    Spectral sensitivity, photographic, 418-9, 441-3
    Spectrograrns (photographic), 410
    Spectrography, 467
    Spectrometer, infra-red, 414
    Speed systems, photographic, 421-3
    Spekker absorptiometer, 413-14
    Spherical aberration, 280, 283, 460--1
    Spherical surface (optical properties), 300, 317-8
    Spindler, R. J., 245 Spinel, refractive index, 236, 242
    Spinning (metal), 14
    Spirit level, 114-17 Spot grinding, 13, 189
    Spot welding, 60
    Springs, 102-4 Squareness, tests for, I87--91
    Stabilisation of steel, 23
    Stainless steel, 25--28 Standard diagram for ray-tracing, 274
    Standard lamps (photometric), 411
    Standard square, 188-9
    Stanhope lens, 289-90
    Steel Stefan-Boltzman law, 380- I
    Steinheil magnifier, 290
    Steinheil telescope objective, 296
    Stereoscopic projection, 373-6
    Stilb, 400
    Stops and diaphragms, 288-9
    Straight edge, use of, 186-7
    Straightness, testing for, 179-87
    Strain Stray light in optical systems, 200
    Striae in glass, 225
    Strip-hinge, 95-90
    Strong, J., 413
    Surface grinding, 11 12
    Surface plate, testing of, 186-7
    Sutherland, G. B. B. M., 383
    Systematic errors, 138-9

    TANGENTIAL IMAGE, 283-4
    Tank development, 437-8
    Tantalum, corrosion resistance, 37
    Taper pins, use of, 66
    Taylor, E. 1%, 290
    Taylor, H. D., 211
    Taylor, Taylor and Hobson Ltd., 111, 133, 365, 367, 368
    Teak, 18
    Tearle, J. L., 309
    Telcothene, 489
    Telegraph Construction and Maintenance Co. Ltd., 439, 489
    Telescope

    Temperature variation, 165-70 Tempering of steel, 22
    Tessar camera lens, 304
    Testing of instruments, 179-91
    Thallium bromide-iodide (KRS-5), 235 Thalliumchloride-bromide (KRS-6), 235 Thermal conductivity Thermal endurance of glass, 231
    Thermal expansion Thermal radiation, laws of, 380-2
    Thermal Syndicate Ltd., 233, 234
    Thermo-couple, 129, 241, 413-14
    Thermo-plastic, 37
    Thermo-relay, 129
    Thermo-setting plastic, 37
    Thermostat, 167-70
    Thick films, interference in, 128
    Thin films, interference in, 127
    Thrust bearing, 141-2
    Tilton, L. W. E., 245
    Time of indication (instrument), 175
    Titanium, corrosion resistance, 37


    [Scanned image of Page 514]

    Titanium dioxide (rutile), refractive index, 236, 242
    T-number (f-number), 309
    Tolansky, S., 128, 129
    Tolerance, 5

    Topaz, refractive index, 236, 242
    Toroidal lens, 308
    Transistors, 394-5
    Transmission, optical, 206-17 Transmittance, 219
    Transpex I, 39: II, 41
    Travelling microscope, errors in, 138-40
    Trichromatic primaries, 353
    Tripoli powder, 259
    Tristimulus values, 351-2
    Trueing tools for glass, 260
    Try-square, 187-8
    Tube length (microscope), 297-8
    Tungsten carbide tools, 9
    Tungsten radiation, 379
    Twyman, 254, 258, 261, 262, 263

    ULTRASONIC DRILL FOR GLASS, 251
    Ultra-violet photography, 466-7
    Ultra-violet transmitting glass, 222
    Under-water photography, 468
    United Kingdom Optical Co. Ltd., 257
    Useful light in instruments, 208-10
    Uviol glass, 222

    VAPOUR-PHASE CORROSION INHIBITORS, 473-4
    Vibration, 146-65

    Vinten high speed camera, 463
    Viscosity of damping fluids, 176
    Vita glass, 222
    Voigt, B., 164-5
    V-value, optical, 198

    WALLIS, E. G., 426
    Walsh, J. W. T., 412
    Washer, F. E., 310
    Watts (Hilger and Watts Ltd.), 124-5
    Wear, in kinematic construction, 89
    Wedge spectrogram, 419
    Welding, 59-61
    Welsbach Mantle, 383
    Weston sensitivity system, 421-3
    Whitehead, T. N., 92, 137
    Whiddington, R., 133
    Wickman gauge, 83
    Wide-angle lenses, 307-8
    Wien's law, 380-1
    Williamson high speed camera, 463
    Wilson, W. H., 129
    "Wind" in instrument bed, 181
    Windows, glass, 324
    Winsor, 349
    Wood, 17-19
    Wratten filters, 223, 450-2
    Wright, W. D., 352
    Wrought iron, 20
    Wunsch, H. L., 98, 99, 100, 101
    Wynne, C. G., 316, 320

    Y-ALLOY, 33
    Young, W. E., 96, 98

    ZINC COATINGs, 484
    Zinc sulphide, refractive index, 236, 242
    Zircon, refractive index, 236
    Zirconium, corrosion resistance, 37


    [Back to Lachlan's Homepage] | [What's New] | [London free Concerts, talks, lectures]

    (This Webpage Page in No Frames Mode)

    If you are feeling sociable, my new E-mail address is [address now invalid] (replace the *at* with an @ ) . Old E-mail addresses might be giving forwarding or reliability problems. Please use clear titles in any Email - otherwise messages might accidentally get put in the SPAM list due to large amount of junk Email being received. So, if you don't get an expected reply to any messages, please try again.