xravity

—A force which gives to every particle of matter a tendency toward every other particle. This influence is conveyed from one body to another without any perceptible interval of time. The weight of the body is the force it exerts in consequence of its gravity, and is measured by its mechanical effects. We weigh a body by ascertaining the force required to hold it back, or to keep it from descending. Hence, weights are nothing more than measures of the force of gravity different bodies. k i 5 In the case of falling bodies, the acceleration due to gravity is 32.16 feet per second in one second; this is indicated by the symbol g. The value of g increases with the latitude and decreases with the elevation. | At the latitude of ) Philadelphia 40°, its value is 32.16. At Paris 48° 50’ N., g = 980.87 cm = 32.181 ft. For ordinary calculations for the United States, g is generally taken at 32.16. ‘rravity Ammeter.—An ammeter in which the index needle is held at zero by the force of gravity, and is drawn away against that force by the action of the current to be measured.