Hallberg, Josef Henrik, 1874- · New York city, The Moving picture world · leaf 167
his method of regulation may be of some advantagein cases where the electric energy stored in the batterycan be made use of for some other purpose. As an illus-tration, I may mention that the energy from the storagebattery could be made use of for the operation of vacuumcleaning motors, or for slot… … storage battery is only about 50 or 60 per cent, of theamount put in, but still it is a saving of at least 50 percent, of the amount generally wasted in the rheostat. Itcannot be said that this method of control is practical,although it may have its application in certain places andunder conditions…
Motion picture theaters · Electric lighting
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
![An illustration from [Graphophone patents] (1878)](https://img.insideoutlibrary.com/img/200/ia-graphophonepaten07unit-543-360.webp)
