040 BOYS' RADIOMICROMETER (c1910)
THE CAMBRIDGE/ SCIENTIFIC INSTRUMENT CO.LTD./ CAMBRIDGE. ENGLAND./ No. 13345 330H ´ 220D.
Circular brass base with three levelling screws and two bubble levels; cylindrical brass case with window for indicator beam and two holes for radiation. Instrument has mirror and thermocouple/coil on quartz suspension with loop between poles of horseshoe magnet.

IR radiation heats a Bi/Sb thermocouple connected to a single turn coil of very low resistance suspended between the poles of a permanent magnet by a quartz fibre. The motion of an attached mirror deflects a light beam reflected to a distant scale. Boys invented the 'bow-and-arrow' method of producing quartz fibres for this instrument. With the aid of a collecting mirror it could detect heat from a candle flame two miles away but it was unable to detect heat from any stars or planets.
References:

  1. C.V. Boys, (1890), Phil. Trans., A, 180, pg 159-186;
  2. M.J.G. Cattermole and A.F. Wolfe , Horace Darwin's Shop (1987) pg 32.
  3. K.Lyall, The Whipple Museum of the History of Science Catalogue 8
  4. ELECTRICAL AND MAGNETIC INSTRUMENTS,item178.

N.H.


60 MICROSCOPE
Munitions Supply Laboratories, Melbourne.
33H
Black lacquered stand with tilting joint. Fast and slow motion adjustments on barrel. 16mm and 4mm objectives fitted to turret. Oil immersion lens missing. x5 and x10 eyepieces. Substage condenser. Australian made in facillities developed during WWII for production of gunsights and other military optical equipment. A number of these microscopes were used for about twenty years in biology laboratories at UQ.
References:

  1. H.C.Bolton, Aust. Phys. pg 27,3,31-43 (1990)

N.H.


205 PETROLOGICAL MICROSCOPE
E.Leitz, Wetzlar, No. 105906
36*16*13
Black enamelled iron stand supports brass tube carrying two interchangeable objectives, "2" and "4",and eyepiece lens . Polarising plates can be slid into the optical path to analyse the polarisation of the light transmitted by the sample which can be mounted on a rotating circular brass stage with a graduated scale. Below the stage is a mirror to reflect light up through the specimen and a Nicol prism can be swung in to polarise the light.

Such microscopes are widely used by geologists to examine thin sections of rock as many minerals can be recognised by their characteristic effects on polarised light.

The substage Nicol prism, eyepiece, and one focussing handwheel are replacements fitted when the microscope was restored by Windsor Davies in 1990.

References:

  1. H.G.Smith (rev. M.K.Wells), Minerals and the Microscope, Thomas Murby and Co., London,1960,pg 5

N.H.


052 CONSTANT DEVIATION SPECTROMETER (circa 1920)
Adam Hilger Ltd., London
42*68*60
Cast-iron tripod stand supporting two perpendicular arms holding a telescope and a collimator respectively. Constant deviation prism set in line with both arms and lies on a turntable linked to a marked drum.

The final deviation of light rays through the prism is always 90° and rotating the prism allows different wavelengths to be viewed. The turntable is revolved by a screw to which a calibrated drum is attached, showing the wavelength being viewed. The system must be 'referenced' by viewing some known wavelength (e.g. the sodium lines), setting the drum to the appropriate mark and clamping the prism to the turntable. The collimator eyepiece houses two small lateral slides able to reduce the viewing area to a small rectangle, designed to reduce eyestrain and improve accuracy.

References:

  1. B.L. Worsnop & H.T. Flint , Advanced Practical Physics for Students(1951), pg 289-293

J.C.


053 SPECTROMETER CAMERA (circa 1920)
Adam Hilger Ltd., London
58*24*21
Wooden casing,; brass arm (containing lens), turn screws and clamps. Photographic plate housing wooden with brass turn screws fro adjusting plate position. Stiff paper and cloth concertina tunnel connecting photographic plate housing to wooden casing and brass arm.Also shutter for exposure. Used with 052 - Constant Deviation Spectrometer to obtain photograph of the viewed spectrum. Able to be shifted laterally so as to view the entire spectrum and also vertically to place one spectrum set above another on the same plate. Can fit up to 4 sets per plate.

References:
F.G.


057 OPTICAL GONIOMETER (Horizontal - Circle Goniometer)
R.Fuess, Berlin-Steglitz
24*20*20
Made in Germany approximately 1890's. It is brass and still has its original lacquered and black enamelled finish. Using a vernier and slow motion tangent screw, angles can be measured to 1 arcmin on the graduated scale. The crystal is mounted on the head, which is adjustable in the x, y and z directions, as well as tiltable in two axes and rotatable around the third. The collimator is fixed to the tripod, while the telescope (missing) is movable. Adjustments critical to the actual measurements are made using a number of thumb screws below the tripod.

To get accurate measurements, small crystals with smooth faces must be used. The goniometer works on the principle of turning the crystal about an axis parallel to the edge between two faces. The image reflected from a second face may be brought into the same position as that formerly occupied by the image reflected from the first face; the angle through which the crystal has been rotated, as determined by a graduated circle to which the crystal is attached, is the angle between the normals to the two faces.

References:

  1. Encyclopedia Britannica 1961, "Goniometer"

M.W.


093 THERMOPILE (c.1910)
Griffin, London
24*10D
A circular brass base supports a vertical brass post with a height adjustment device. Atop the post sits a hollow brass case with three windows, one with a shutter attachment, and containing a stack of two types of metal rods. Extended from the top of the brass case are two electrical connectors.

Visible or infrared radiation beamed into the window with the shutter attachment causes one end of the metal lattice inside the brass case to heat up. Due to the physical properties of the two unlike metals, usually bismuth and antimony (or silver), an electric current will flow from the bismuth to the antimony at the heated end, whilst in the opposite direction at the unheated side. The metal rods are arranged electrically in series so that they produce an electric current great enough to be measured by a galvanometer attached to the connectors.

References:

  1. Textbook of Physics, Duncan and Starling, Macmillan and Co. p380-382, 1024-1025.
  2. Dictionary of Applied Physics, edited by Sir Richard Glazebrook, Vol. IV, p428.

C.M.


106 WEBER PHOTOMETER

Max Kohl, Chemnitz (c 1920?)

50*50*20

Two polished brass tubes are connected with a rotating joint in a T-configuration. The cross-bar has an eyepiece at one end while the other tube carries a lamp housing on a telescopic section with rack-and-pinion adjustment.

The purpose of the photometer is to make a measurement of a light source's intensity by direct comparison with a known, standard source. The photometer works by an observer making a comparison (with the eye) of the light intensity of two unpolished disks, of which one is movable in the horizontal tube. Enclosed in the perpendicular tube is a Lummer-Brodhun cube consisting of two right-angled prisms which, over a small circular area in the centre of their hypotenuse faces, are in optical contact. Such a cube allows the two illuminated discs to be viewed simultaneously and their brightness compared. The perpendicular tube, which is rotatable, is readily focused onto the light source to be studied. The angle through which the arm is turned is merely read off the mounted graduated arm. A small standard lamp (ideally, 20mm in height including the flame) is utilized, together with the inverse-square law, for comparison of the light intensity. A special mechanism on the photometer allows the height of the lamp to be adjusted.

References: B.K. Johnson, "Practical Optics" - Benn Bros, London 1922.

WS


112 LUMMER-BRODHUN PHOTOMETER

Max Kohl, Chemnitz

29 x 8 x 15

    This is a simpler version of the Weber Photometer (#106).  The device's purpose is to compare the brightness of an unknown source with that of a standard and, by use of the inverse-square law, calculate the luminosity of the unknown source.
    The device consists of a metal box, with two entrances and an eyepiece, and a slot for a white magnesium carbonate slab mounted between the two entrances.  Light from two sources (one standard and one of unknown luminosity) strike the white slab.  Some of the scattered light is reflected towards a Lummer-Brodhun cube by the use of two right-angled prisms.  The Lummer-Brodhun cube consists of two more right-angled prisms, one of them with the hypotenuse rounded off except for a circular region, which is placed in contact with the hypotenuse of the second prism.  Hence while all light rays from one of the sources are reflected to the observer, only the central light rays from the second source are transmitted to the observer.  The observer sees two circles, one smaller than and superimposed on the other.  The human eye can compare the brightness of the two circles, and the distances to the sources can be adjusted until they are of equal brightness.  Then
                    L1/d12 = L2/d22.
 

References:

Worsnop, B.L., Flint, H.T., Advanced Practical Physics for Students, Methuen and Co. Ltd, London, 1951, .

PAP


113 FLICKER PHOTOMETER (c1912)
Max Kohl, Chemnitz
32*11*20 cm
Contained inside a semi-cylindrical box is a series of rough surfaced white plates that are placed orthogonally to each other and facing outwards whilst attached to a wheel. On each side of the box is a window made of glass and attached to the system is an adjustable eyepiece with one convex lens which looks through a circular opening at the white plates.

The procedure of the flicker photometer is that light passes through the glass, striking the white plates and is diffusely reflected through the eyepiece to the observer. The plates are positioned so that they are at an angle of 45o to the windows and aligned alternately so that when the wheel is rotated, the plates reflect light alternately from each window, thus causing a flicker.

The photometer is attached to a sturdy but simple mount that has a well defined angular scale at the opposite end to the eyepiece so the photometer can rotate about an axis passing through the eyepiece. With the whole system made of lacquered and black brass (except the glass windows and lens), it all rests on a simple extendable stand.

Since 1906, flicker photometers have been mainly used and documented for heterochromatic photometry. Being a simple and portable photometer independent of colour difficulty, it is suitable for use in streets and in buildings and for any area where lighting needs to be tested. It can be easily converted to be powered from a constant energy source, such as an electric generator.

References:

  1. Flicker Photometry, J.S. Dow. Philosophical Magazine 1906 vol. 12 p.130.
  2. Optical Convention (1912), Catalogue of Optical and General Scientific Instruments, p.190-191.
  3. E. Grimshell (1933), A Textbook of Physics, Blackie and Son Ltd., London & Glasgow, p.25-28.
  4. R. Glazebrook (ed.) Dictionary of Applied Science, vol. 4 (1923), Macmillan Co. Ltd., London, p.410, 411, 453-458.

J.C.


114 PRISM SPECTROMETER
W. Wilson 1 Belmont St., London, NW
76*32*24
An iron tripod stand supports two arms holding a collimator and a telescope (both 26 cm in length and at a height of 33 cm) and a marked turntable (approximately 12 cm in diameter) with a 360o scale with two vernier scales marked 1 and 2. The collimator can rotate around the turntable and consists of a lens toward the prism and at the outer end a slit whose size is regulated by means of a screw on the left-hand side. The telescope can rotate along with the scale. The prism table and scale are free to rotate and the table can be adjusted to be precisely horizontal by means of three spring mounted screws. The height of the table from the tripod base is adjustable via a horizontal screw. The turntable is marked by three parallel lines, seven concentric circles, five small holes and three small indentations.

Spectrometers are used in spectroscopy for chemical analysis and they paved the way to a previously unimagined branch of physics-astrophysics, which deals with the physics and chemistry of heavenly bodies. Rays of light enter the collimator through a slit, whose size is adjustable to trade off resolution against brightness, and is at the focus of the collimator lens which renders the light parallel before falling onto the prism. The rays undergo refraction and the light gets dispersed into its spectrum which is viewed through the telescope. Angular measurements of the light's deviation are made with the divided circle which reads with a vernier.

References:

  1. J.A. Bennett, The Celebrated Phenomena of Colours: the early history of the Spectroscope. Published to accompany a special exhibition at the Whipple Museum of the History of Science.

B.K.


115 POLARIMETER
Franz Schmidt and Haensch, Berlin, S, No. 8878
85*25*47
Iron stand which supports a sample tube between two Nicol-prisms - a polariser and an analyser. As monchromatic light passes through the tube, the plane of polarisation of the light will rotate if the sample is optically active. A stand is provided for a Bunsen burner to heat the sample.

The rotation is measured by turning the analyser to match the intensities of two areas with different polarizations, and reading the scale which is provided with two verniers reading to 0.01o.

The amount of rotation is proportional to the concentration of the sample. Therefore polarimeters were used in industries dealing with the production of sugar, starch, jam, condensed milk, wine, oils and drugs.

References:

  1. British Optical Instrument Manufacturers' Association (Issued by), Dictionary of Scientific Instruments, Constable and Co. Ltd., London, 1921, p.140.
  2. H.J. Cooper, Scientific Instruments, Hutchinson's Scientific and Technical Publications, London, 1946, p.43-50.

R.W.


051 BECKMAN DB GT GRATING SPECTROPHOTOMETER (c 1967)

Including Instruction Manual 566-F (dated April 1967)

Beckman Instruments, Inc. Cat. No.: 156801

25*59*36

Metallic housing, with sample placement door at front. Front panel controls for photomultiplier offset and calibration and wavelength selection. Relative absorption read from a meter at front, or may be connected to a chart recorder. 220V, 1A, 50Hz power supply. Ports at the rear allow the circulation of coolant through sample chamber.

Light from either a tungsten lamp (visible) or a hydrogen lamp (UV) is split into two beams. A grating is used to isolate a particular wavelength for study. One beam passes through the sample being analysed and the other is a reference, and the beams are detected by a photomultiplier. A signal is then produced which indicates the relative absorption of that wavelength by the sample. The grating may be set to scan across the available wavelengths at a constant rate and the results recorded by a chart recorder (not present). A coolant circulation system was an optional feature which has been installed on the device (probably added subsequent to purchase).

The primary uses of such a spectrophotometer were biological assays, analysis of biological samples and the study of the rates of production of reaction products in the life sciences. The device on display was in use by the Biochemistry Department at The University of Queensland until 1991 and was certified as serviceable by that department 03/04/90. It appears undamaged and in fair operational order.

References:

1. Harrison Stephens, Golden Past - Golden Future, The First Fifty Years of Beckman Instruments, Inc. Claremont University Centre, 1985.

2. Edisbury, J., Practical Hints on Absorption Spectrometry, Plenum, NY, 1967.

3. Lothian, G., Absorption Spectrophotometry, Hilger, London, 1958.

4. Mellon, M., Analytical Absorption Spectroscopy, J. Wiley, London 1950.

5. Varma, A., CRC Handbook of Atomic Absorption Analysis, Vol. 1, pp.3-37.

6. http://www.beckman,com

MH


292 FILTER SPECTROPHOTOMETER

EEL International Ltd

45*23*30

A cast - alloy case supports a tungsten lamp, interference filter, sample holder, photo cell, galvanometer and case cover.

Light from the source tungsten lamp passes through the interference filter and samples to the photo cell, then the transmitted intensity is displayed by the galvanometer.

The tungsten-halogen (usually as quartz - iodine) lamp is constructed with a compact tungsten filament. It's advantage is higher energy in the 300-400 nm range.

The interference filter consists of an evaporated coating of layers of transparent dielectrics of alternating high and low refractive index.

The band of wavelengths transmitted varies across the filter so that wavelength can be scanned from 400-700 nm by moving the filter sideways using a control knob at the front. This allows the absorption spectrum of the sample to be roughly judged, or quantitative measurements of the absorption at a particular wavelength to be made.

References: T. Buckley, N.G. Kents, J. Roberts, J. Wolfenden and G.A. Woolsey, Instrument maintenance and operation for laboratory assistants, I.D.P. (1985) p.79-115.

TN


338 COINCIDENCE OPTICAL RANGE FINDER (Entfernungsmesser 14 nr 500S)

Carl Zeiss, Jena

100*10*10

Metal cylinder of about 10 cm in diameter stands on a tripod. Objective lens with rotating cover at each end and eyepiece at centre. Thumbwheel adjustment at right side. This instrument was used to determine the distance to an object with the use of mirrors and lenses.

The coincidence range finder could be summed up as being made up of two simple telescopes separated by a known distance. With a target object located and a range needed, the range finder is adjusted so that the two fields of view from the two telescopes are given in a single field of view. One is inverted in a central window. This view may be observed through the eye piece located at the centre of the range finder. The two images are brought into coincidence horizontally by adjusting a roller geared to a distance scale.

This technology was primarily developed for the use in artillary in war. With the range to the enemy vital, range finders where easy to use and fairly accurate. They have also been used in such things as range finders for cameras as well as particular surveying jobs.

Reference: E.B. Brown, Optical Instruments, Chemical Publishing Co., NY, 1945, p.361-370.

AM


341 OPTICAL PYROMETER (c 1940)

Leeds and Northrup Co./Philadelphia USA/Model No. 8622/Serial No.724733

29*17*31

Grey metallic control box containing galvanometer, standard cell, four dry cells, resistors, two slidewires and knobs; connected to a scope by black cable; scope consists of lenses, switch, filament, lamp and a means for focusing.

Current from the cells act upon the set of resistors. One of these, R2, is variable and can be controlled by the use of the large knob on the side of the box. The scale of R2 is calibrated in degrees Celsius, and is carried with its dial. As the resistance is varied, the filament in the scope alters in brightness until it matches the source, leading to the term "disappearing filament pyrometer". Temperature is read directly from the scale.

Designed to be portable, this model is missing the carry strap. It measures a temperature range from 775-2800 degrees Celsius.

References:

1. Directions for No. 8621, No. 8622 and No. 8623 Optical Pyrometers, Leeds and Northup Company, Philadelphia (n.d.)

2. Wood, W.P., Pyrometry, McGraw-Hill Book Co., 1941, pp.114-116.

AK


351 SPECTROMETER

Bellingham and Stanley Ltd., London/No. 529502

76*32*18

An iron tripod stand supporting two arms, holding a collimator and telescope, and a turntable marked with a 360o scale. The collimator consists of a lens toward the turntable and at the outer end a slit whose size is regulated by means of a screw. The telescope arm can rotate around the turntable and has a second telescope mounted below the main telescope which allows an engraved glass scale on the underside of the turntable to be read. Both collimator and telescope are fitted with polarizers with circular brass scales.

Spectroscopy is the science of the determination of a substance's chemical make-up by observation of its spectrum. Light enters the collimator and is focussed by the lens so that parallel light is incident on the prism. The light is then refracted by the prism and its constituent wavelengths dispersed to form the spectrum. The spectrum is observed through the telescope and the angular deviation of the dispersed light is measured. From this the spectrum is determined and chemical analysis of the object being observed can be performed.

This spectroscope was used by the Department of Physics at the University of Queensland in its undergraduate laboratories.

References:

1. J.F. James and R.S. Sternberg, The Design of Optical Spectrometers, Chapman and Hall, London 1969.


362 MACBETH ILLUMINOMETER

Leeds & Northrup Company/ Philadelphia USA / Patent nos: 704976, 705105, 705057

42*25*18

Instrument consists of three main parts: the illuminometer proper, a controller, and a reference standard. All are stored in a black case, dimensions of which are 42x25x18 cm. Also included in the case are various accessories, including three electrical cords. This device was used as a portable illuminometer. The illuminometer proper is a black tube, 23 cm long and 4.5 cm in diameter. It operates by comparing the brightness of a surface with a translucent lamp of known intensity at a variable distance within the illuminometer. One of the accessories within the case is a white test plate, with essentially constant brightness from all angles of observation. The scale of the instrument, at one end of the illuminometer proper, is calibrated in foot-candles, and the user standardizes it themselves to allow for the absorption of the surface. The controller consists of a battery for operating the lamps, a milliammeter for use with the standard lamps, two close-regulating rheostats, and a double-throw switch. The reference standard consists of a metal housing in which is mounted a standardized lamp. It is used, along with the test plate, to calibrate the illuminometer.

References:

  1. H.A.E. Keitz. Light Calculations and Measurement. Macmillan and Co Ltd, London, 1971, p. 371.
  2. W.B. Boast. Illumination Engineering. McGraw-Hill Book Company, New York, USA. 1942, p. 48.

C.R.M.


367 SP600 SERIES 2 VISIBLE ABSORPTION SPECTROMETER

Unicam Instruments Ltd, S.V. No. 408-S-10. No. 49985, c.1960?

40*50*20

The spectrometer is housed in a metal case finished with a blue enamel paint (measuring roughly 40 x 50 cm at the base and around 20 cm high). A standard white incandescent bulb serves as a light source which may be passed through a few coloured filters before entering the housing itself. The beam is collimated using curved mirrors and a prism is used in conjunction with a plane mirror to select the wavelength of light to be used. This is arranged so that the only light to pass into the sample is the light that passes through the prism to reflect off the mirror and travel back through the prism in exactly the right direction to be fed into the sample chamber. The light passes through a slit before entering the sample chamber and passing through the sample to a photo-multiplier tube which produces a signal to be amplified by a valve, then causing a rotating scale similar to the wavelength selector to display the transmitted intensity of light.

The size of the slit before the sample chamber is regulated by a finely tapped screw in combination with a series of thin metal sheets as springs. This assembly is designed to possess almost no backlash. The slit itself is a curved shape to eliminate the aberration produced when imaging a straight slit with curved mirrors. Throughout the whole instrument, very careful design and construction are used to make it very precise.

The spectrometer is the instrument around which the vast field of spectroscopy is based. This field has application in almost every area of science today, from the analysis of stars, galaxies and other bodies in space, right down to being instrumental in the determination of the structure of the atom. The absorption spectrometer is used to study the interaction of partially transparent substances with light - specifically how much light is transmitted and absorbed. For example, they enable the accurate determination of the absorption of coloured indicators allowing the progress of chemical reactions to be monitored.

The SP600 Visible Absorption Spectrophotometer was released in the mid 1950s and became the industry standard for visible spectrometer round the world. The continued in production until 1976 and there are many such instruments in laboratories even today. This one was used in a laboratory at Greenslopes Hospital.

Reference:

  1. Unicam web site - http://www.unicam.co.uk

N.L.


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