.S7A 1 WILLIAM Sli:.ME.\S, F.R.S. 



137 



for the greatest possible length of time. This was a desideratum 

 which ought to be met, and the conditions on which it ought 

 to be met were not manifold. They would find that they would 

 come very much to a definite mode of operation or construction 

 in applying all these different requirements. 



MR. SIEMENS believed he had succeeded in making this pole 

 equally strong in all respects. The strain applied at the top would 

 ix/rhaps Ixiiid the whole pole over to such a point as to approach 

 the ultimate strength ; then it would be matter of accident 

 whether it broke in the cast iron. Most likely it would break near 

 the ground line in the cast iron. There was an advantage he 

 believed in the base plate being flexible it saved the pole giving 

 way in this joint. It would begin to yield a little, and if the 

 ground was not firm possibly it might lift the earth up ; but that 

 he considered was the most likely point where the pole would give 

 way. It would be useless to make it firmer in the earth than it 

 was now. 



THE STEAMSHIP "FARADAY" AND HER 

 APPLIANCES FOR CABLE-LAYING, 



BY C. WILLIAM SIEMENS, D.C.L., F.R.S, M.R.I.* 



THE speaker in his introductory remarks observed that an elec- 

 tric telegraph consisted essentially of three parts, viz., the electro- 

 motor or battery, the conductor, and the receiving instrument. 

 He demonstrated experimentally that the conductor need not 

 necessarily be metallic, but that water or rarefied air might be 

 used as such within moderate limits ; at the same time, for long 

 submarine lines, insulated conductors strengthened by an outer 

 berthing were necessary to ensure perfect transmission and im- 

 munity from accident. The first attempts at insulation, which 

 consisted in the use of pitch and resinous matters, failed com- 



* Excerpt Journal of tbe Royal Institution of Great ISritain, Vol. VII. 1874, 

 pp. 310-313. 



