1 66 THE ADDRESSES, LECTURES, ETC., OF 



(which I need hardly say is a strictly private document) on the 

 24th December, 1866, that is to say, some time after the principle 

 in question had been communicated at Berlin to a number of 

 scientific men. In order to improve his position, Mr. S. Alfred 

 Varley, in his previous letter of the 5th November, 1877, shows 

 that his machine had been constructed in September, 1866, or 

 three months previous to his application for provisional protection ; 

 Mr. Sabine in his letter brings forward proof that a machine was 

 constructed for the late Sir Charles Wheatstone somewhat previous 

 to Mr. S. Alfred Varley's date ; and I am in a position to state 

 that the machine upon which the first experiments were tried at 

 Berlin (a Wippe or automatic current reverser) had actually been 

 constructed several years previous to 1867. The explanation of 

 this fact is simple, and is contained in my letter to you of the 

 30th October last, viz., that the dynamo current is produced by 

 simply turning an electro-magnetic engine what may be termed 

 "the wrong way." The mere circumstance, therefore, that the 

 apparatus used in these experiments had been constructed previous 

 to 1867, proves simply nothing, except perhaps the futility of 

 tracing the origin of a discovery from any other date than that of 

 its first publication. 



Mr. S. Alfred Varley endeavours to throw a doubt upon my 

 brother's first publication of the accumulative principle by the fact 

 that we applied for certain letters patent involving that principle 

 sixteen days later, and concludes "that business men are not in the 

 habit of invalidating their patent rights by publishing their inven- 

 tion before provisional protection has been obtained or at least 

 applied for." Mr. S. Alfred Varley seems to have lost sight of 

 the fact, that the enunciation of natural principles belongs to pure 

 science, and does not form a legitimate subject for a patent, 

 whereas applications of those principles to useful purposes, and 

 combinations of parts to give effect to such useful applications, are 

 what does form a proper subject for a patent. In searching further 

 Mr. S. Alfred Varley will find not one but several such patents 

 taken out by my firm since 1866, leading up step by step to the 

 light-producing machine now adopted by the Elder Brethren of 

 the Trinity House. Yours faithfully, 



C. WILLIAM SIEMENS. 



12, QUEEN ANNE'S GTATE, December 10, 1877. 



