which are not imposed equally upon the same products imported from different countries. — Differential
galvanometer (Elec.), a galvanometer having two coils or circuits, usually equal, through which currents
passing in opposite directions are measured by the difference of their effect upon the needle. — Differential
gearing, a train of toothed wheels, usually an epicyclic train, so arranged as to constitute a differential
motion. — Differential motion, a mechanism in which a simple differential combination produces
such a change of motion or force as would, with ordinary compound arrangements, require a considerable
train of parts. It is used for overcoming great resistance or producing very slow or very rapid motion. —
Differential pulley. (Mach.) (a) A portable hoisting apparatus, the same in principle as the differential
windlass. (b) A hoisting pulley to which power is applied through a differential gearing. — Differential
screw, a compound screw by which a motion is produced equal to the difference of the motions of
the component screws. — Differential thermometer, a thermometer usually with a U-shaped tube
terminating in two air bulbs, and containing a colored liquid, used for indicating the difference between
the temperatures to which the two bulbs are exposed, by the change of position of the colored fluid, in
consequence of the different expansions of the air in the bulbs. A graduated scale is attached to one
leg of the tube. — Differential windlass, or Chinese windlass, a windlass whose barrel has two
parts of different diameters. The hoisting rope winds upon one part as it unwinds from the other, and
a pulley sustaining the weight to be lifted hangs in the bight of the rope. It is an ancient example of a
differential motion.
Differential
(Dif`fer*en"tial), n.
1. (Math.) An increment, usually an indefinitely small one, which is given to a variable quantity.
According to the more modern writers upon the differential and integral calculus, if two or more quantities
are dependent on each other, and subject to increments of value, their differentials need not be small,
but are any quantities whose ratios to each other are the limits to which the ratios of the increments
approximate, as these increments are reduced nearer and nearer to zero.
2. A small difference in rates which competing railroad lines, in establishing a common tariff, allow one
of their number to make, in order to get a fair share of the business. The lower rate is called a differential
rate. Differentials are also sometimes granted to cities.
3. (Elec.) (a) One of two coils of conducting wire so related to one another or to a magnet or armature
common to both, that one coil produces polar action contrary to that of the other. (b) A form of conductor
used for dividing and distributing the current to a series of electric lamps so as to maintain equal action
in all. Knight.
Partial differential (Math.), the differential of a function of two or more variables, when only one of the
variables receives an increment. — Total differential (Math.), the differential of a function of two or
more variables, when each of the variables receives an increment. The total differential of the function
is the sum of all the partial differentials.
Differentially
(Dif`fer*en"tial*ly) adv. In the way of differentiation.
Differentiate
(Dif`fer*en"ti*ate) v. t.
1. To distinguish or mark by a specific difference; to effect a difference in, as regards classification; to
develop differential characteristics in; to specialize; to desynonymize.
The word then was differentiated into the two forms then and than.
Earle.
Two or more of the forms assumed by the same original word become differentiated in signification.
Dr.
Murray.
