Electrical and scientific instruments and apparatus : november 20th, 1899 (1899)
Elmer G. Willyoung & Co · New York : E.G. Willyoung · leaf 114
(Table shown in Fig. is not furnished.) In reversing the Bunsen screen (or any other screen of the Willyoungmake) the screen turns upside down, and not as in most screens previouslyused, through 180° of horizontal arc, in the latter case requiring the photo-meter far enough from the wall for the… … Fig. 94. W4596. W4594. Rotator |30 00 For obtaining Mean Horizontal Candle Power; complete and ready forbelting to driving motor. The lamp rotates upon a, vertical axis driven bya small motor or other outside source of power through an intermediatefriction pulley. A simple variable clutch allows…
Electric apparatus and appliances · Equipment and supplies
Internet Archive · Medical Heritage Library · Public Domain Mark 1.0. Free to use for anything.
![An illustration from [Graphophone patents] (1878)](https://img.insideoutlibrary.com/img/200/ia-graphophonepaten02unit-312-142.webp)