26 



NATURE 



[November 9. 189; 



simply drawing attention to the most prominent land- 

 marks, which may be used as points from which to carry 

 out the triangulation, and as stations on which to set up 

 the necessary delicate instruments of observation. Dr. 

 Werner von Siemens was a remarkable man ; he had a 

 most successful career ; he left indelible marks on the 

 progress, both scientific and industrial, of his day, and 

 there are lessons to be learnt from his work, and from 

 his systems and methods. 



Let us rest here a moment. This factory was just the 

 very thing that was required at the time. The two 

 members of the firm were — the one, Dr. Werner Siemens, 

 a m:i;> possessing clear scientific views of natural forces 

 and phenomena, and an inventive mind ; the other, Mr. 

 Halske, a man thoroughly acquainted with mechanics, 

 the use of machines and tools, and possessing the skill 

 to make, and to teach others how to make, delicate 

 mechanism. There was a demand in Germany, in 

 Russia, in England, and elsewhere, for what they could 

 make ; their work was thoroughly to be relied upon, and 

 orders streamed in on them. 



Dr. Siemens says somewhere in this volume that every- 

 thing he has done for natural science has been due to a 

 claim made upon him by applied science. It was the ab- 

 solute necessity under which he was to make accurate 

 measurements that set him to work to invent an exact 

 standard of resistance, possessing which he was after- 

 wards able to elaborate a rational method for testing the 

 electrical condition of submarine cables. Previously to 

 this, Jacobi's standard, which was a determined length of 

 copper wire of a determined section, was used at the 

 Berlin factory, but copies of these standards were found 

 to dift'er so much that Dr. von Siemens set to work to in- 

 troduce a standard of his own. In revolving this matter 

 in his mind he came to the conclusion that " it was both 

 desirable and convenient to be able to combine a definite 

 geometrical notion with the unit of resistance." He there- 

 fore used mercury,the only metal fluid at ordinarytempera- 

 tures, whose resistance cannot be affected by molecular 

 variations, made a series of important experiments, and 

 finally having defined his unit as a metre length of mer- 

 cury of a square millimetre section at o' C, he sent copies 

 of his standard to physicists and telegraph engineers 

 suggesting their use in determinations of resistance. We 

 refrain from entering into a discussion as to the relative 

 values of units, whether Weber's absolute unit, the B.A. 

 c.g.s. unit, the ohm, or others ; the main point is that Dr. 

 von Siemens wanted a clearly defined unit, he had found 

 the absolute necessity for it in his electrical work, and 

 now possessing it he was able to press forv/ard to other 

 achievements. Here was a decided step in advance. 

 Measurements which had previously been variable were 

 now uniform, tests which formerly could not have been 

 made could now be applied, and work which was formerly 

 •carried on more or less by rule-of-thumb, could new be 

 done with a certainty of result. 



We have referred to submarine telegraphy as one of the 

 great achievements of this century, and the brothers Sie- 

 mens, Werner, William and Carl, have taken a share in 

 it. Almost every submarine cable of importance has been 

 shipped from the Thames. The first tentative efforts 

 were made in England, and the final successful results 

 have been achieved here. Cable-laying is now one of the 

 NO. 1254, VOL. 49] 



scientific arts, and our author has had a large share in 

 making it so. 



We are here brought face to face with the two sides of 

 the question, the scientific and the technical, and at the 

 same time with two national characteristics, the com- 

 bination of which has produced these results : English 

 enterprise, German investigation. And there is yet 

 another link in this chain of events, which it is difficult 

 to see how we could have done without, the finally unsuc- 

 cessful but at the time needful and useful practical ex- 

 periment of underground cables in Prussia. " My friend 

 Halske " . . , " was the first to encounter these pheno- 

 mena."' " Halske found, first of all, that with shorter 

 lines our self-interrupting indicator telegraphs acted with 

 much greater speed than corresponded to the resistance 

 of the line. When communication between Berlin and 

 Cothen had been established, a distance of about 95 

 English miles, the giving apparatus ran with double 

 velocity, whilst the receiving apparatus stopped altogether. 

 This at the time inexplicable phenomenon occurred the 

 earlier the better the lines were insulated, which induced 

 Halske purposely to impair the insulation of the line by 

 the addition of artificial watery by-passes." " When the 

 underground line had been extended to Erfurt, Halske's 

 watery by-passes were no longer sufficient. But mean- 

 while I had become convinced that the peculiar behaviour 

 of the underground wires could only be ascribed to the 

 electrostatic charge already observed at the testings in 

 the factory, the wire namely forming the inner, the damp 

 soil the outer coating of a Leyden jar." " The very sur- 

 prising and disturbing phenomena of electrical charges 

 in underground conductors required thorough study. 

 Further, it was necessary to establish a system for the 

 determination of the situation of faults in the conduction 

 and insulation of underground wires by measuring cur- 

 rents at the end of the wires. The uncertainty of the 

 measurements of currents led to the necessity of replac- 

 ing them by resistance measurements, and thereby to the 

 setting up of fixed reproducible standards of resistance 

 and scales of resistance. For this purpose the methods 

 and instruments for current and resistance measurements 

 had also to be improved and adapted for technical use ; 

 in short, a whole series of scientific problems had cropped 

 up, the solution of which was called for by technical 

 needs." 



And so later on, when the actual problems of submarine 

 telegraphy had to be solved. Dr. Werner took his share 

 in their solution all the more ably because of the ex- 

 perience he had already gained, and of his system of 

 studying the science on which the art was founded. 

 His narrative, especially in this connection, is full of 

 adventures, not unaccompanied with danger, the descrip- 

 tion of which is always interesting and often graphic. 



The lesson of the life, of which a few personal recol- 

 lections are given in this volume, appears to be this : Find 

 out the work you were sent here to do, and do it with 

 your might. All the work that has to be done is not 

 great work, but may be good work for all that ; it may 

 not lead to honour and fortune ; but it has to be done, 

 and if you are the one who has to do it, do it well. 



Dr. von Siemens had a work to do ; it matters little, it 

 seems to us, whether others were engaged on the same 

 work or not ; he did his share. As to who the person is 



