20
M A GNETISM.
ELECTRO MAGNETISM.
£ s. d.
Faraday’s apparatus, for shewing the rotatory motion of the magnet round the pole of the voltaic battery, and the motion of the pole round the magnet . 110 0
Ampere’s apparatus for shewing the rotation of the
battery round the magnet . . 6s. to 0 10 6
Marsh’s vibrating wire . . . 3s. to 0 10 0
Barlow’s wheel for converting ditto into rotatory
motion . . . . . . 15s. to 1 1(1 0
Copper frame on a stand for shewing the deflection of the needle,which maybe converted into rotatory motion . . . . . . 15s. to 1 0 0
Spiral on a stand for magnetizing needles . 5s. to 0 10 0 Soft iron of the horse shoe form in a spiral of copper wire, for exhibiting the very powerful effects of making magnets in the voltaic circuit 10s. to 110 0
Apparatus for shewing the rotation of the magnet upon
an axis round the pole . . £1 10s. to 2 10 0
Ditto, on its centre, being in the voltaic circuit
.£1 10s. to 3 3 0
De La Rive’s floating apparatus, for shewing the directive force of an electrified wire . 5s. to 0 10 0
Galvanometer for exhibiting very feeble electric currents . . . . . . 10s to 1 10 0
Compound frames, bars, and wires of the different
metals for exhibiting thermo electric effects .000 Ritchie’s Tortion Galvanometer, for ascertaining the relative deflecting forces of currents of voltaic electricity . . , . . 16s. to 1 10 0
Compound rectangular frames for exhibiting rotation
round the poles of the magnet . . 15s. to 110 0
Cylindrical form batteries, well calculated for electro
magnetic experiments . . . 10s. to 1 10 0
Dr. Roget crosses of ivory, shewing the direction of
electro magnetic currents . . . .036