.sYA' WILLIAM SIEMENS, /\A\S. 289 



(litliculty was experienced with meters having counters working in 

 water, although they might perform very correctly when tested in 

 the shop, and for some time after being fixed ; he had always found 

 they became incrusted sooner or later, according to the peculiarities 

 of the water, interfering with the accuracy of working ; although 

 brass remained clean much longer than iron, and the deposit was 

 found to take place much less upon the parts in motion than upon 

 those at rest. 



Ho thought there would be a source of inaccuracy in the use of 

 t\vo modes of delivery of the water at different times, the small 

 jet for the slowest velocities, and the full width of orifice for the 

 other cases, as the force of impulse in a small jet was more in the 

 proportion of the square of the velocity, so that a double velocity 

 of jet would drive the drum three or four times faster instead of 

 only twice as fast, which would be required for correct measure- 

 ment of the stream of water issuing ; also the indirect action of 

 the stream on the circumference of the revolving drum, being 

 partly by impulse and partly by friction, gave too uncertain a 

 moving force to form a correct principle of measurement. From 

 his experience he did not think that wheelwork could be kept in 

 correct working order for a long time if exposed to ordinary water, 

 and this difficulty would apply more strongly to any self-acting 

 adjusting valve at the inlet orifice to be opened by the current of 

 water, and regulate the area of discharge upon the drum. 



OX AN IMPROVED WATER METER. 

 By MR. C. WILLIAM SIEMENS.* 



In January, 1854, the writer communicated to this Institution 

 a paper on an improved water meter, in which he described several 

 mechanical arrangements, by which he had succeeded in measuring 



* Excerpt Minutes of Proceedings of the Institution of Mechanical Engineers, 

 185(3, pp. 113-120 and 123. 



VOL. II. u 



