TUNING FORKS 1401
A set of eight tuning forks one each of C (256) D E F G A B C (512) supplied in a velvet lined case. (Individual Tuning Fork of any one frequency can also be supplied.). Frequency / Note:
(a) 256 / c
(b) 288 / d
(c) 320 / e
(d) 341 / f
(e) 384 / g
(f) 426 / a
(g) 480 / b
(h) 512 / c

TUNING FORKS ON RESONANCE BOX 1406
Four tuning forks of different frequencies mounted on a wooden resonance box with a striking hammer to demonstrate the production of beats.

ELECTRICAL TUNING FORK 1408
On a sturdy streamlined base with provision for horizontal and vertical use. Fork made from a special steel prong size 300x25xl0mm chromium plated gives 60v.p.s. electromagnet works on 6 volts. Amplitude of vibration can be varied by sliding the electromagnet inside the prongs.

ORGAN PIPE 1414
Varnished wood with glass front and membrane suspended on cord for loading with sand to show position of modes and antimodes.

ORGAN PIPE SLIDING 1415
Made of square section of polished wood and fitted with a tapered mouthpiece. It has a sliding square graduated piston to give a diatonic scale from C256 to C512.

BELL IN VACUUM, GLASS 1419
An electric bell working on 2-4V D.C. suspended in a 150x100mm glass bell jar with connections to the two terminals on a rubber bung sealing the bell jar. For use on a pump plate of dia 150mm.

RESONANCE APPARATUS SIMPLE 1420
Comprises two metal tubes, one sliding in the other to change the resonant length of the air column set up by a vibrating tuning fork. The outer tube is fitted on a wooden block.

RESONANCE APPARATUS 1422
Consists of a brass nickel plated resonance tube of 100cm length fitted on a wooden stand. A brass reservoir slides over a metal rod supported on the base. The reservoir can be clamped at desired position to change the level of water in the metal tube. The level of water can be read against a meter scale in a glass/polystrene transparent tube fitted on the wooden plank. Complete with rubber tubing.

RIPPLE TANK 1426
The apparatus consists of tray (Size : 590 x 510 x 70mm approx.) with detachable four legs having leveling screws. Its edges formed into 'beaches' to minimize the unwanted reflection of waves. The tank is provided with a drain hole closed with a rubber bung. Light alloy uprights to carry a horizontal rippler support rod are provided, height of the rippler assembly can be adjusted easily and precisely. The rippler assembly elastically suspended from its support rod, consists of a 4-6V D.C. motor mounted on a wooden beam (size : 280 x 30 x 20mm). The motor is fitted with an eccentric mass to give oscillations to the beam. Two plastic spheres mounted on right angled rods fitted into the beam may be adjusted to any required separation. A light alloy rod fixed centrally to a socket in one short side of the tank provides support for the illuminant. Two straight obstacles 130mm long one straight obstacle 40mm long and a curved reflector of 200mm radius are provided to perform various experiments. A plastic tray to accommodate all the fittings except the legs is provided. The legs and tray can be placed in the tank recess without any damage or scratching the upper surface. Supplied with power supply.

RESONANCE APPARATUS 1427
Glass tube approx. 84cm. long and 2.5cm. diameter, mounted on a stand with clamp and boss, with 500ml. glass bulb, connecting tubing and spring clip supported on iron ring.

HAND STROBOSCOPE 1429
A slotted metal disc with a finger hole is pivoted on a bearing mounting provided with a handle. The disc has 6 radial slots of 50 x 3mm extending to its edges. Disc dia 250mm.

STROBOSCOPE (Xenon) 1430
The instrument is housed in a strong metal case provided with carry handle and rubber feet. An inclined rear panel carries the flash rate control, range selector, sockets and switch for external synchronization, and the power ON/OFF switch.

ELECTRICAL VIBRATOR 1431
For Melde's and other experiments. A steel rod is clamped near one end through two 4mm terminals. The rod passes through a small solenoid and between the poles of a magnet. Adjustable contact points fitted through a second pair of terminals make alternating connection with an adjustable contact on the rod. The rod has a small hole at one end for the attachment of thread which passes over a bench mounting pulley and supports a scale pan. For 2V A.C. supplies. With pulley & clamp, scale pan.

SONOMETER 1434
Comprises a hollow wooden rectangular box with 100cm scale on both long edges, three wires, sliding wedges, adjustable pulley and keys mounted, on metal supports.

WAVE FORM APPARATUS 1439
For demonstration of longitudinal and transverse waves. Comprises 24 eccentric discs supporting a series of metal brass. On revolving the handle,16 straight rods give transverse wave and 8 bent rods give longitudinal waves in a running guide.

WAVE FORM HELIX 1440
Steel wire close-wound Helix of 19mm diameter, closed length 3 meters extendable to approx. 9 meters, with looped ends

WAVE FORM HELIX (SLINKY) 1441
Helical coil of flat section, tempered steel wire. Coil dia. 75 mm. Length closed 110 mm.

POWEL'S WAVE MACHINE 1442
For demonstration of the movement of progressive transverse waves. Comprises 22 balls on wire rods, with eccentric motion attachment, driving handle & fitted on base.

MELDE’S APPARATUS 1444
To demonstrate stationary waves by means of stretched string. Consists of electrical tuning fork, bench clamp pulley, scale pan and cord.

SIREN WITH INDICATOR 1445
It consists of a air chamber and a rotating disk having circles of holes. When the disk is rotated by blowing air, a shrill sound is produced. By means of a worm gear the number of revolutions is recorded. Mounted on a base.

WHIRLING TABLE 1446
Stand overall height 43 cm. for use in vertical or horizontal position, fitted with handwheel and wire helix belt drive to pulley. Suitable for use with Savart wheel and disc and adopter to accommodate colour discs.

SAVART’S TOOTHED WHEEL 1448
Four toothed wheel each of 7.5 cm diameter, spaced 6 mm. apart on a shaft with projecting spindle with slight taper at its end. For use with whirling table.

LIGHT GUIDE DEMONSTRATOR 1449
An S-shaped acrylic bar 220 x 20 x 20mm which can be used with the Ray Box to demonstrate total internal reflection and help students to understand the principles of optical communications. The bottom of the bar is painted white to aid visibility.

WHISTLE 1450
Cylindrical, mouth-blown type.

SIREN DISC 1452
The disc has four sets of drilled holes arranged in co-centric circles. The number of holes in each circle are 34,45,54 and 72 respectively. For use with whirling stand.

DOPPLER EFFECT DEMO KIT 1454
Consists of 3 precision machined aluminium alloy tuning forks with holes in the stems to accept a heavy braided cord. Kit contains 256Hz and 1,024Hz forks, 50Ft cord, and tuning fork activator.

CROVA’S DISC 1456
For showing progressive waves. Printed on a white plastic disc which is free to rotate in an outer case. Size: 225x225mm, with viewing slot.

WAVE MOTION MODEL 1457
A great illustration of wave motion, this mechanism demonstrates longitudinal and transverse waves by hand-cranking a set of eccentric aluminium disks. Model is mounted on a sturdy wooden base.

WAVE STICKS SET 1458
Demonstration set used in the exploration of wave speed; reflection and refraction polarities, and transformers and impedance. Includes one assembled unit and 400 sticks, with special narrow tape to construct another. Includes instructions.

WAVE MOTION APPARATUS 1459
The inertia of the massive rods makes for slow and majestic displays of torsional waves that appear as transverse waves when viewing the colorful ends of the rods. Wave fundamentals are easily introduced and include frequency, wavelength, amplitude, reflection and phase. Can be also operated in vertical format. Size: W 30cm x L 90cm.

VIBROGRAPH 1461
This is an instruments for teaching the principle of indirect measurement. The stylus of the tubing fork and the needle on the pendulum each make a trace on the smoked glass plate as the carriage is moved from right to left. Prior to the "run" the pendulum frequency is measured by timing with a stopwatch. The unknown frequency of the tuning fork is then determined by comparing the traces.

EVEN FREQUENCY TUBING FORK SET 1463
Six unmounted tuning forks precision machined from aluminum alloy. Set consists of 125Hz, 250Hz, 500Hz, 1000Hz, 2000Hz and 4000Hz.

ADJUSTABLE TUNING FORK 1465
Precision-grade aluminium alloy tuning fork with sliding weights on each tine. Weights adjust to deliver tones in C-128, D-144, E-160, F-170.7, G-192, A-213.3, and B-240 frequencies. Overall length, 8”.

RUBBER HAMMERS 1468
Used to activate tuning forks. Available with a soft, medium, or hard sphere and mounted on a sturdy, wooden handle.
(a) Soft (Frequencies of 32 to 256Hz)
(b) Medium (Frequencies of 256 to 1024Hz)
(c) Hard (Frequencies of 1024Hz)

ACOUSTICAL PHYSICS DEMONSTRATION 1473
Consists of one 880-Hz aluminium alloy tuning fork, a rubber striking pad, and one 880Hz ames tube (a half-wave open tube to produce an integrally coupled tuning fork resonator). Can be used to demonstrate sympathetic vibration, "beat" phenomenon, energy transfer, Doppler effect, and more.

KUNDT'S TUBE APPARATUS 1475
Consists of a glass tube heavy walled 1350 x 32 mm with cork bung, short & long ebonite rod, cork pistons, mounted on a polished wooden board 1520 x 125 x 22 mm with spring clamps. The long ebonite piston is supported by wood clamp secured with wing nuts.