The current is sent in one or the other direction or is cut off in
practice to produce the desired oscillations of the coil b b. A glass
siphon n l works upon a vertical axis l. One end l is immersed in an ink
well m. Its longer end n touches a riband of paper o o. The thread k
attached to one side of the coil pulls the siphon back and forth
according to the direction of current going through the electro-magnet
cores. A spiral spring adjusted by a hand-screw controls the siphon. In
operation the siphon is drawn back and forth producing a zigzag line.
The upward marks represent dots, the downward ones dashes. Thus the
Telegraphic Code can be transmitted on it. To cause the ink to issue
properly, electrification by a static machine has been used, when the
stylus does not actually touch the paper, but the ink is ejected in a
series of dots.
Fig. 286. SIPHON RECORDER.
Reducteur for Ammeter.
A resistance arranged as a shunt to diminish the total current passing
through an ammeter. It is analogous to a galvanometer shunt. (See
Multiplying Power of Shunt.)
Reducteur for Voltmeter.
A resistance coil connected in series with a Voltmeter to diminish the
current passing through it. Its resistance being known in terms of the
resistance of the voltmeter it increases the range of the instrument so
that its readings may cover double or more than double their normal
range.
Reduction of Ores, Electric.
Treatment of ores by the electric furnace (see Furnace, Electric.) The
ore mixed with carbon and flux is melted by the combined arc and
incandescent effects of the current and the metal separates. In another
type the metal is brought into a fusible compound which is electrolyzed
while fused in a crucible. Finally processes in which a solution of a
salt of the metal is obtained, from which the metal is obtained by
electrolysis, may be included. Aluminum is the metal to whose extraction
the first described processes are applied.