W.
(a) A symbol or abbreviation for watt.
(b) A symbol or abbreviation for work.
(c) A symbol or abbreviation for weight.
Wall Bracket.
A telegraph bracket to be attached to the external walls of buildings to
which wires are attached as they come from the poles to reach
converters, or for direct introduction into a building.
Wall Sockets.
Sockets for incandescent lamps constructed to be attached to a wall.
Ward.
Direction in a straight line; a term proposed by Prof. James Thompson.
The words "backward" and "forward" indicate its scope.
Water.
A compound whose molecule consists of two atoms of hydrogen and one atom
of oxygen; formula, H2 O.
Its specific gravity is 1, it being the base of the system of specific
gravities of solids and liquids.
If pure, it is almost a non-conductor of electricity. If any impurity is
present it still presents an exceedingly high, almost immeasurable true
resistance, but becomes by the presence of any impurity an electrolyte.
Water Equivalent.
In a calorimeter of any kind the weight of water which would be raised
as much as is the calorimeter with its contents by the addition of any
given amount of heat received by the calorimeter.
Waterproof Lamp Globe.
An outer globe for incandescent lamps, to protect them from water.
Watt.
(a) The practical unit of electric activity, rate of work, or rate of
energy. It is the rate of energy or of work represented by a current of
one ampere urged by one volt electro-motive force; the volt-ampere.
It is the analogue in electricity of the horse power in mechanics;
approximately, 746 watts represent one electric horse power.
Ohm's law, taken as C = E/R, gives as values for current, C and E/R, and
for electro- motive force C R. In these formulas, C represents current
strength, R represents resistance and E represents electro-motive force.
Then a watt being the product of electro-motive force by current
strength, we get the following values for rate of electric energy, of
which the watt is the practical unit: (1) E2/R -- (2) C*E -- (3) C2 * R.
The equivalents of the watt vary a little according to different
authorities. Ayrton gives the following equivalents: 44.25 foot pounds
per minute--.7375 foot pounds per second--1/746 horse power. These
values are practically accurate. Hospitalier gives .7377 foot pounds per
second. Hering gives .737324 foot pounds per second, and 1000/745941
horse power.