What is a flashlight?

The flashlight is a small portable electric lamp, operated by dry cells. It has a metal case, usually in the shape of a tube, but sometimes of rectangular or square design. It has two or three dry cells, connected in series, that give a voltage of 2.5 to 3.5 volts. It often has a lens in front of the bulb for directing the light produced by the tiny flashlight bulb. Pressure on a button, located on the side of the case, completes the electric circuit from the batteries to the filament of the bulb. The light can therefore be controlled by pressure of the thumb on this button. Flashlights were first produced in New York around 1900. By 1914 they had completely supplanted the oil lanterns that policemen used. Many flashlights now manufactured have devices for adjusting the beam; some can give a directional beam up to 100 yards.