Abstract :
It will be remembered that we started to build arc light dynamos in Philadelphia and ran the first machine at the bakery all night during the summer of 1879. The machine was run in a room which was sometimes during the summer at a temperature of 140 deg. fahr, by the thermometer, the machine being near the bake-ovens. The test was a severe one, but the machine did not burn out and is still in a working condition, after having been used for a long time after the bakery trial. There were some things about this machine which may as well be mentioned. It was, without doubt, the first three-phaser built. Its circuits were arranged so that it could be used with four separate circuits, or a series of four arc lamps at 20 amperes, or with 8 or 9 arc lamps with 10 amperes. To get the proper perspective it must, of course, be known that electric lighting in any form was a rarity in those days.
