.S7A 1 //7/./././.!/ SIEMENS, /-.A'.-V. 187 



..at. and the weight should be increased. If the case is doubtful 

 I \vould put on a considerable amount, say three or four cwt. 

 'I'll is would (if a great deal of slack is being paid out) stop 

 the brake-wheel, and the ship will pass over the ground without 

 paying. 



In I hf discussion of ike Paper 



<>X SOME RECENT IMPROVEMENTS IN DYNAMO- 

 ELECTRIC APPARATUS," bj RICHARD WILLIAM 

 HKNKY PAGET HIGGS, LL.D., Assoc. Inst. C.E., ami 

 JOHN RICHARD BRITTLE, Assoc. Inst. C.E., 



Di;. SIKM.KXS* said, although the authors were connected with 

 him in business, the paper had been written without reference 

 to himself. It set forth correctly the scientific principles upon 

 which the action of the dynamo-electric machine and electric 

 lamps was based, and stated in moderate terms the results that 

 had been practically arrived at. For years past the marvels of 

 the electric light had been spoken of ; but it was only within 

 the last year that effects had been produced which would bear 

 comparison with other practical methods of obtaining light. The 

 most remarkable results had been realised, by the experiments 

 extending over six months, at the South Foreland by Dr. Tyndall 

 and Mr. Douglass, the Chief Engineer of Trinity House. A 

 careful analysis of the amount of the light, its nature, its per- 

 manency, and the conditions under which it was produced by 

 different machines, had resulted in the recommendation of the most 

 approved machine for extended application to lighthouse purposes. 

 In estimating the power of a new agent of that kind, it was safer 

 to iro to first principles and see what consumption of coal was 

 necessary to produce a given effect of light, and to contrast it 

 with the amount of carbon consumed in burning oil or gas. This 



* Excerpt Minutes of Proceedings of tbe Institution of Civil Engineers, 

 Vol. LI [. Session 1877, 1878, pp. 57-59, 60. 61, 80, 81. 



