1 14 ELECTRIC LIGHTING. 



this is the unit of moving force which corresponds with our 

 kilogrammetre ; it is equal to a kilogrammetre divided by 



7'233- 



The Report of the English Commission assigned the 

 superiority to Siemens' machine (small form). According to 

 Tyndall this form is best adapted for connecting with ma- 

 chines, and in proportion to its small size its effects are 

 enormous. We must remark, however, that the figures given 

 in the table on pages 125 and 126 for the Gramme machine, 

 relate to machines of the pattern of 1875. Now, the new 

 patterns of 1876 have given results infinitely superior, not 

 only with regard to the yield of the Gramme machines tried 

 in England, but also with regard to the Siemens machines 

 extolled by the English Commission. According to the ex- 

 periments made in France the values relating to the Gramme 

 machine should be rectified as follows : 



With a machine weighing 175 kilogrammes, making 850 

 revolutions per minute under a motive power of 2^ horse- 

 power, the condensed radiating power would be 4,297 

 candles, and diffused radiating power 2,590, which would 

 give for each horse-power 1,719 for the condensed and 1,036 

 for the diffused radiating power; the Gramme machine 

 would then take the first place in order of merit. 



The following are the conclusions of the American Com- 

 mission : 



Af er having carefully considered all the facts noted in the 

 reports which have been submitted to it, the Commission has 

 unanimously come to the conclusion that the small form of 

 Brush machine, although in some respects less economical than 

 the Gramme machine or the large Brush machine, for the 

 general production of light and of electric currents, is, of all the 

 machines experimented with, the best adapted to the wants of 

 the Institute, chiefly for the following reasons : 



i. It is admirably arranged for the production of currents 

 of very different intensities, and it produces a good light. 



It is remarkable for the way in which the various mechanical 



