Rotation of Liquids, Electro-magnetic.
The rotation produced in a liquid carrying centripetal or centrifugal
currents by an electromagnet. It is practically an intensification of
electro-dynamic rotation. (See Rotation of Liquids, Electro-dynamic.)
Rubber.
In a frictional electric machine the cushion of leather which is pressed
against the plate as it rotates.
S.
(a) Symbol for second.
(b) Symbol for space, or length; L is preferable.
(c) Symbol for south-seeking pole of a magnet.
Saddle Bracket.
A bracket carried on the top of telegraph poles, carrying an insulator
for the upper wire.
Safety Device.
(a) A device to prevent overheating of any portion of a circuit by
excess of current. It generally consists of a slip of fusible metal
which if the current attains too much strength melts and opens the
circuit. To ensure its breaking a weight is sometimes suspended from the
strip. In one form an insulated German silver wire is wrapped around the
end of the fusible strip a number of times and its end is connected to
it. The other end of the German silver wire connects with the main lead,
so that all the current goes through both in series. If the German
silver wire becomes heated from excess of current the coil wrapped
tightly around the end of the fusible strip melts it and opens the
circuit.
(b) Lightning arresters, q. v., may be cited under this heading.
Synonyms--Automatic Cut Out--Safety Fuse, Plug, or Strip.
Fig. 299. COCKBURN SAFETY FUSE.
Safety Fuse.
A strip of metal inserted so as to form part of a circuit and of such
size that a smaller current [than] would heat the regular wire of the
circuit dangerously, so as to cause a conflagration for instance, would
melt the fuse and open the circuit. As it sometimes happens that a
safety fuse melts without parting a weight is sometimes hung upon it, so
as to break it as it softens.
Salt.
A salt is a chemical compound containing two atoms of two radicals,.
which saturate each other. One atom or radical is electro-positive
referred to the other, which is electro-negative. By electrolysis salts
are decomposed, the atoms or radicals separating and uniting to form new
molecules.