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8 between which the vibrators are fixed in an oil bath. The whole is fixed on the base V, and the levelling screws, F, F, F, are added.

Types 1 and 2 may be used with a falling plate or cinematograph camera.

Type 4.—This type has been specially designed for teaching and lecture purposes. Wave forms having a total amplitude of 1 metre can be thrown on a screen. For this purpose the whole of the suspended system has to be greater in size than either Types 1 and 2, besides requiring a much larger current.

The normal scale distance for projection work is 3 metres, at which distance the deflection on each side of zero may be 50 cms. The maximum R.M.S. current through the vibrators should not exceed 0'5 ampere. Each vibrating loop is made as a complete unit, these being separately removable and interchangeable. Each instrument holds two of these units. The same electro-magnet is used for Types 1 and 4.

Accessories for recording and observing are supplied for use with the oscillographs. Fig. 1 shows a complete outfit for use on a 25,000-volt circuit, consisting of a permanent magnet oscillograph and a falling plate camera. For long records a cinematograph film camera may be employed, enabling records up to 50 metres in length to be obtained; With the Type 4 oscillograph a tracing outfit, consisting of a synchronous motor which drives a vibrating or rotating mirror may be used. This vibrating mirror reflects the moving spot of light on to a sheet of tracing paper, on which the curve of E.M.F. or current may be traced.

Le texte affiché peut comporter un certain nombre d'erreurs. En effet, le mode texte de ce document a été généré de façon automatique par un programme de reconnaissance optique de caractères (OCR). Le taux de reconnaissance estimé pour cette page est de 99,93 %.

La langue de reconnaissance de l'OCR est l'Anglais.