MIRROR STRIP 1201
Black silvered with protective coating. Sizes:
(a) 75 x 25mm
(b) 100 x 40mm
(c) 150 x 50mm

MIRROR SUPPORT BLOCK 1202
Simple wooden block 35 x 35 x 35mm with slot to take mirrors.

CONCAVE MIRRORS 1206
Optically worked, silvered back with protective coating.
(a) Diameter 50mm F.L. i) 100mm ii) 150mm iii) 250mm
(b) Diameter 75mm F L. i) 100mm ii) 150mm iii) 250mm

CONVEX MIRRORS 1208
Optically worked, silvered back with protective coating.
(a) Diameter 50mm F.L. i) 100mm ii) 150mm iii) 250mm
(b) Diameter 75mm F L. i) 100mm ii) 150mm iii) 250mm

CYLINDRICAL, MIRROR CONCAVE 1211
Semi-circular mirror, 150mm dia x 25 mm high. Made of stainless steel.

CYLINDRICAL, MIRROR CONVEX 1212
Semi-circular mirror,150 mm dia x 25 mm height. Made of stainless steel.

LENSES DOUBLE CONVEX SPHERICAL 1216
Optically worked ground edges.
(a) Diameter 50mm F.L. 50mm
(b) Diameter 50mm FL. 100mm
(c) Diameter 50mm F.L. 150, 200, 250, 300mm

LENS DOUBLE CONCAVE 1218
Optically worked with ground edges.
(a) Diameter 50mm F L. 50mm
(b) Diameter 50mm FL. 100mm
(c) diameter 50mm F.L. 150, 200, 250, 300mm

MAGNIFYING, READING GLASS (Handy) 1220
With metal frame and bakelite handle, chrome plated, packed in cardboard box. Dia / Magnification:
(a) 50mm / 3.5X
(b) 50mm / 3.5X
(c) 60mm / 2.25X
(d) 75mm / 2.5X
(e) 100mm /2.5X
(f) 100mm / 2.25X

GRATICULE MAGNIFIER 1221
A sophisticated high power stand magnifier with a graticule (recticle) holding attachment. Uses highly corrected precision optics to give fully colour corrected distortion-free and perfectly flat field upto the edge. Has a clear acrylic stand that allows ambient light illumination of object and graticule. Provided with spiral twist mechanism for precision focusing, and a focus lock ring. Ideal for engineering applications like checking small parts, linear measurements, angles, hole dia., thread size and thickness. With the appropriate graticule it is an invaluable aid as graphic arts comparator for type, spacing and size. Also useful for proof reading and editing, aerial photo checking and geological sand checking. A choice of fifteen different graticules is available for varied applications. The unit is provided with protective moulded case and a dust cover. Magnification8 x, Field of View 22 mm, Work Distance 20 mm.

LENSES SET OF SIX 1222
50mm dia optically worked with ground edges comprises one each of double convex, plano-convex, concavo-convex, double concave, plano-concave and diverging concavo-convex. Supplied in velvet lined case.

LENS HOLDER 1224
Comprising a metal holder with sides grooved to hold lens or mirror. The holder is finished in matt black and is free standing for bench use to hold lens 50 mm dia.

GLASS BLOCK RECTANGULAR 1230
A bubble free glass block polished from all sides.
(a) 75 x 50 x 18mm
(b) 100 x 60 x l8mm

HOLLOW GLASS PRISMS, CUBES AND TROUGHS 1231
From ordinary glass plates properly cemented with optical cement
A - Size 38 x 38 mm Hollow Prism
B - Size 50 x 50 mm Hollow Prism
C - Size 75 x 50 x 18 mm Hollow Slabs
D - Size 60 x 60 mm Hollow Trough
E - Size 75 x 75 mm Hollow Trough

GLASS PRISM EQUILATERAL 1232
Made from moulded glass equilateral. Sizes:
Size: (A) 38 x 38mm (B) 50 x 50 mm

HOLLOW GLASS PRISMS 1233
From solid glass blocks, with sides plane plates for Spectrometer work in velvet-lined case
A - Size 38 x 38 x 25 mm
B - Size 38 x 38 x 38 mm
C - Size 50 x 50 x 50 mm

LENS/FILTER HOLDER 1234
These Optical Bench Holders allow for precious positioning of lenses, filters, targets and other optical elements. The holders may be attached directly to our 0.50" post or to any of our small base plates. Delrin clamp pad does not scratch optics.

GLASS PRISM RIGHT ANGLE 1235
90º 45º 45º prism made from moulded glass.
(a) 38mm height
(b) 50mm height

SET OF ACRYLIC PLASTIC BLOCKS 1236
Clear acrylic plastic blocks 20mm thick with bottom surface finished in white to show ray tracks and all other surfaces fully polished. The set comprises seven blocks as follows.
(a) Rectangle 70x50 mm.
(b) Triangle 90x45x45, 75mm hypotenuse.
(c) Triangle 60x60x60, 57mm side.
(d) Semi-circle 75mm diameter.
(e) Bi-convex 75mm long, curved faces,115mm radius.
(f) Bi-convex 75mm long, curved faces, 145mm radius.
(g) Bi-concave 75mm long, curved faces,115mm radius.
All packed in velvet lines box.

PERSPEX BLOCK, RECTANGULAR 1237
Rectangular of clear perspex, all faces fully polished.
Size: 115 x 60 x 20mm approximately.

PERSPEX BLOCK, SEMICIRCULAR 1238
Made of clear perspex, all faces nicely polished 80mm dia and 20mm thick approximately.

PHOTOMETER JOLLY’S 1239
Block comprising two pieces of polythene approx. 25 mm square 10 mm thick separated by tin foil, on stand behind aperture 12 mm dia.

DEMONSTRATION MODEL OF ASTRONOMICAL TELESCOPE 1241
Complete with 38mm dia lenses in metal holders mounted on wooden board which has a diagram showing the course of rays.

DEMONSTRATION MODEL OF GALLILIAN TELESCOPE 1242
Complete with 38mm double concave lens eyepiece and a double concave lens objective in metal holder mounted on wooden board having a diagram showing the course of rays.

ASTRONOMICAL TELESCOPE 1244
50mm dia achromatic objective glass, 10x Ramsden eyepiece, focusing by rack and pinion. Supplied with a folding tripod stand with adjustable height.

RAY TRACK APPARATUS 1245
Wood board with matt white surfaces, mounted on plastic feet carries a circular scale with 0-360° four quadrants 0-90° graduated every 2°, removable turntable 170 mm dia. with 2 lines at right angles and a Ray Box with a 12V, 24W bulb. Supplied with a cylindrical convex lens focal length 75 mm and two double screens, giving one wide slit and one each single, three and five slits.

RAY OPTICS BOX 1246
Black finish metal box, with 12V 24W straight filament lamp. The lamp holder, with 1mt. of twin flex wire is mounted in metal bridge piece. The enameled steel body has slots to support a cylindrical lens and a triple slit screen. Extra slots are provided for filters. Dimensions 182 x 61 x 115mm high. The box is supplied complete with lamp and triple slit but without lenses or filters.

RAY OPTICS KIT 1247
Kit consists of two lamp holders, each in metal shade with two axial slots and mounted on metal support rod. Holder complete with approximately 1.2m 2-wire P.V.C. covered cable and 12V, 24W axial filament lamp. One each right and left hand cylindrical lamp shields, in matt black finish light alloy sheet with slot parallel to axis. Two black “combs”, with 17 equi-speed parallel slots, two black plastic plates, each with single and triple slits, two comb and plate holders, a spring loaded clip mounted on metal support bracket, four metal light-barriers, four each plano convex cylindrical lenses, 50 x 50mm, +7D, two each cylindrical lenses 50x50mm, respectively, plano-convex +10D, +17D, plano concave -17D.

PIN HOLE CAMERA 1248
To illustrate images produced by small apertures. Comprising a polished wooden box with a ground glass screen at one end and a hole at the other.

PINHOLE CAMERA KIT 1249
The kit consists of the following items.
8 cardboard boxes 150 x 100 x 100 mm with hole, screen and lid.
50 sheets of black paper 200 x 250 mm
1 lamp 200WATTS
1 mounted lamp holder with flex
1 packet of pins

SET OF COLOUR FILTERS 1250
A set of three primary and four secondary colour filters suitable for use with ray box mounted in card board frame size 50 x 50 mm. Plastic mounts also available.

NEWTON’S COLOUR DlSC APPARATUS. 1251
Demonstrates that mixed spectral colours produce white when rotated rapidly. Comprises of a metal disc 150mm dia having 7 colours (VIBGYOR) in their right proportions, mounted on a metal stand.

NEWTON’S RING APPARATUS 1252
Comprises a plano-convex lens 60mm dia and l00cm focal length. On a flat glass plate equal dia. Both enclosed in a ring frame with compression adjusting screws.

REFRACTIVE INDEX OF A LIQUID BY CRITICAL ANGLE METHOD 1253
The apparatus consists of a cemented glass trough, air cell rotatable by knob carrying pointer on circular scale graduated 360°. Fitted on bridge.

SPECTROSCOPE, Simple (Direct Vision, Hand) 1254
A wide spectrum through 10x10mm size, 3 element type optical glass prism, telescopic focusing brass body, precision slit adjustable by knurled head rotatable ring.

SPECTROSCOPES WITH SCALE (Direct Vision) 1255
Direct wave length readings 400nm to 750nm each div. represents 5nm, with sodium D-line scale and spectrum is viewed in the same field. Precision slit and focusing control with D-line adjustments for error free readings.

LIGHT BOX AND OPTICAL SET (HODSON LIGHTBOX) 1256
This kit contains a light box and collimating lens, together with a full set of precision lenses and prisms, colour filters, coloured cards, half round and parabolic mirrors, spare lamp, comprehensive instruction and experiment manual. Two integral hinged mirrors permit the blending of 3 colours on a screen for study of colour mixing. The precision and unique design is virtually unbreakable. Power requirements 12V A.C. or D.C. at 3 amps. All parts are available separately. Spares for Above:
(a) Only light box with lamp and slits
(b) Lens and mirror pack
(c) Set of colour filters
(d) Spare lamp

DIFFRACTION GRATINGS 1257
Photographic replica gratings mounted on plate glass and suitable for visual. Grating size, 25 x 25mm, on glass plate 50 x 38mm. The gratings are of:
(a) 300 lines/mm
(b) 600lines/mm.
(c) 2400lines/inch.
(d) 7500lines/inch.
(e) 15000lines/inch.

ROTATABLE OPTICAL DISC HARTLEY'S 1258
A 30 cm dia., white painted steel disc marked from 0 to 360° at every 1°, with centre mark, on a stable cast iron base. The main disc and the lamp house (with 12V, 24W bulbs) can be rotated and held in any desired position. With the lamp house, a rotatable disc with single, double, triple and quadruple slits and with adjustable lens carrier with lens for divergent, parallel or convergent light beams is provided. Optical elements provided for reflection are 50 x 25 mm, plane glass mirror, and a polished plated metal cylindrical mirror. Optical element for refraction is semi-circular, bi-convex, bi-concave, right angle prism and trapezoidal acrylic blocks. These Optical elements have powerful magnets attached for fixing of blocks to the disc.

METERSTICK OPTICAL BENCH SET 1259
Sufficient for optical experients in high school physics. Set Includes 2 end supports, 2 Lens holders, object marker, screen, screen with millimeter scale, Complete with Meter Stick.

OPTICAL BENCH WOODEN 1260
Wooden base with 1mt. scale graduated in mm. Complete with two lens holders, one candle holder, pin hole plate, ground glass screen, wire gauze screen and a needle stand with index mark.

SODIUM LAMP HOUSE AND TRANSFORMER 1261
Heavy base with 500 x 12.5 mm anodized aluminum rod (upright) carrying lamp house and aperture with holder adjustable for height. Complete with transformer but without Sodium Lamp.

OPTICAL BENCH, 1 meter 1264
One meter long, for advanced research work consists of two rods, one stainless steel and one chrome plated. The stainless rod is engine divided in mm. These are supported on heavy cast iron feet, with leveling screws. Four special designed metal sliders having a fine index mark enables reading to be taken on the scale with ease and accuracy. The sliders are machined metal so they slide accurately and smoothly on the’ bed. Two of the sliders have transverse slow motion adjustment. Complete with 6 accessories (two lens holders, two optical pins; one candle holder and one screen ground glass).

OPTICAL BENCH (1½ meter) 1264-A
Same as above, but 1½ meter long.

CROSS WIRES 1268
A circular blacked metal screen 75mm dia, with a 10mm dia aperture and cross wires of 26 s.w.g. Mounted on a 6 mm brass rod giving a center height of 80 mm approx.

PRISM FOR SPECTROMETER 1270
Equilateral optically worked two faces polished, crown glass refractive index 1.5165. and Flint glass refractive index 1.5793.
(a) 25 x 25mm height
(b) 32 x 32mm height
(c) 38 x 38mm height

SPECTROMETER BASIC 1272
The base integral with collimator tube support, carried the swinging telescope arm provided on a bearing with spring loaded and thrust plates, this type of bearings eliminates any slack which would otherwise develop with wear. The collimator and telescope tubes are one-piece precision casting in light alloy, concealed helical-action focusing devices are provided. The collimator slit with spring-loaded jaws is of a new and robust design which ensures retention of the initial accuracy. The graduated prism table support, 18cm dia, is divided in degrees, the vernier, reading of 0.1degrees, is fixed to the telescope arm. Large diameter clamping knobs are fitted for movement control and fine adjustment is provided for the telescope. All bright parts are chromium plated with the base and tubes in synthetic (hammer) finish.

SPECTROMETER, INTERMEDIATE 1275
This is a robust instrument designed specifically for student use which nevertheless is capable of very high performance. The main structure is of heavy cast metal, with bright plated fittings.
A - Scale: The 150mm diameter circle with protective shield is fixed to the telescope movement and the table is attached to the double-ended rotation fine adjustment screws, and release of a clamping screws enables adjustment of both movements to be made by hand.
B - Collimator: Mounted on fixed and fitted with 178mm focus achromatic objectives, 25mm clear aperture. Also fitted is a unilaterally adjustable slit, 7mm long.
C - Telescope: Mounted on moveable pillar and fitted with 178mm focus achromatic objective, 25mm clear aperture. Also fitted is a 8x Ramsden eyepiece and a glass crossline graticule. Both the telescope and collimator have rack and pinion focusing. Means are provided for leveling the axis of both optical units and for squaring them to axis of rotation.
D - Prism Table: The table is marked with lines to assist placing the prism will respect to the table leveling screws.

MICROMETER SLIT 1276
Circular black metal screen, 75mm diameter with a 12.5mm central aperture. A screw-controlled, spring-loaded precision slit is mounted on one side of the disc. Maximum slit opening 4mm, with a heavier screw thread, carrying a drum which is divided into fifty divisions giving a reading of 0.01mm, an index is provided with a 5mm scale divided in 0.5mm divisions.

MILLIKAN’S OIL DROP 1277
The apparatus comprises the following componants:

THE CONDENSER: The specially designed condenser consists of two horizontal brass plates 5cms square. The plates are separated by insulating spacers having a separation of 4.5mm. The upper plate perforated at the centre for passage of oil Drops into the observation chamber is fitted to the lower plate by 2 ebonite shrouded screws to facilitate opening of the condenser for cleaning. The condenser is provided with two slits, one for viewing the droplets and the other for projection of light.

CONDENSER BOX: For completely eleminating the disturbances due to air currents, the condenser is now housed in a transparent perspex box 9x6x5cms(LxWxH) with a removable lid. A sensitive circular spirit level is fixed to the instrument. The condenser unit is mounted on a pillar, fitted to a massive cast iron base with levelling screws. At the centre of the box lid a hollow cylinder is mounted. The oil is sprayed through the cylinder, which can be closed by a piston. The box is fitted with two terminals, having connections with the condenser plates for H.T. Supply.

LAMP HOUSE: A metal case with a 6 V incandescent bulb is mounted on a fixed arm. fitted to the pillar of the instrument. Light is projected to the field of view for illuminating the droplets.

THE TELE-MICROSCOPE: Instead of a microscope the instrument is now fitted with an extra powerful short focus tele microscope. The magnification of Tele-microscope in respect to it’s objective is I, thus making it Direct Reading i.e. the exact distance travelled by the droplets can directly be read on micrometer scale. The Tele- microscope is fitted with achromatic objective, ramsden eye piece and a micrometer scale of 0.1mm. The Tele-microscope is fitted with micrometer screws for it’s precise adjustment is horizontal & Vertical plane.

THE SWITCH: A specially designed switch for off and on the charge and for reversing the polarity of the condenser plates, is fitted on the base. The switch is fitted with four terminals for connections. Finished in Tilden Gray and Bright Chrome the instrument is supplied with instructions for use and complete with Atomizer. Oil and 8 extra glass plates.

ACCESSORIES (OPTIONAL):
A. Regulated power supply 0 to 300 Volts.
B. Power supply 0 to 500 V with intensity control arrangement.
C. Atomiser for a forceful spray for the best charged droplets.
D. Spray oil (water free) non volatile bottle of 150g.

TRAVELING MICROSCOPE 1278
A heavy cast iron base fitted with leveling screws top machined over which slides a metal carriage which can be clamped at desired position. The stage carries a vernier that travels over a stainless steel scale graduated in mm 0 to 16.5cms. A gunmetal pillar fixed to the stage has an embedded S.S. Scale graduated 0 to 15cms and carries a vertical traveling carriage with vernier. Horizontal stage for placing objects is fitted with milky plate. The microscopic tube on vertical traveling carriage is focused by rack and pinion and has an achromatic objective, a Ramsden eye piece 10X and a cross line graticule. Vernier read- in .01 mm supplied in wooden case. The above list does not include the entire range of instruments available, please feel free to request other items throughout this field.

POLARIMETER 1280
For the measurement of angle of rotation of optically active substance in solution i.e. angle through which the plane of polarised light is rotated on passing through a specified length of solution of known concentration. Specific rotation may then be determined. The circular head is attached near the analyser and vernier movement on the scale enables the reading of optical rotation accurate up-to the accuracy of 0.10. Soleil's Bi-Quartz Laurents half shade device which makes the instrument accurate and simple for use with white light (day light) or sodium light. The polarimeter tubes made from Borosilicate glass with fittings at both ends. The tube end covers with glass round disc, optically true with rubber washers to make it leakproof. Complete with a set of two polarimeter tubes (100mm and 200mm) in wooden case, nicely polished.

STANDARD READING TELESCOPE WITH SCALE 1281
The telescope is mounted on a specially designed carriage with support ring to stop abrupt falling. The carriage is fitted with two adjustable screws for precise vertical and horizontal positioning. This arrangement is mounted on a 25 mm dia. 450 mm long steel pillar, fitted on a cast iron base with leveling screws. A scale holder is provided with scale.

POLARIODS 1282
Universal size. Can be easily fitted to any telescope or collimator. Mounted on a graduated 360° degrees circular scale with pointer.

NEWTON'S RING MICROSCOPE 1284
This is a compact instrument with full arrangements for conducting Newton's Ring Apparatus. A standard microscope with 30X magnification is provided with a rotatable cross-line and the eye piece can be focused at the individuals requirements. The microscope tube unit can be raised or lowered and clamped at any desired position. The focusing of microscope is through rack and pinion. The longitudinal movement of the microscope saddle for the purpose of measurement of rings is done by rotating the drum provided. The 26mm movement can be read by the scale and divided drum to 0.001cm. This set consists of one optical flat glass and one plano-convex lens (100mm radius) arranged inside a metal case resting over the stage of the instrument which is adjustable for the alignment of the measuring line. The condenser lens is provided in front of the reflector. In case the Ring set is removed from the stage, the instrument can be used as a simple compact measuring microscope.

ASTRONOMICAL TELESCOPE MODEL 1285
Complete with lenses, mounted on metal base with diagram of rays shown for demonstration.

GALILEAN/GALLEON TELESCOPE MODEL 1286
Complete with lenses, mounted on metal base with diagram of rays shown for demonstration.