360 MAETIN BRIMMER. 



insulation of the secondary coil. He concluded that, if this were divided 

 into sections properly insulated from each other, the device would be 

 more efficient and give a longer spark. On trial, his expectations were 

 realized. One of these coils was exhibited at a meeting of the British 

 Association held in Dublin in 1857, and afterwards at the University 

 of Edinburgh. A description of Ritchie's coil was published in 

 Silliman's Journal and in the Journal of the Franklin Institute. 

 M. Ruhmkorff procured one, and, copying it successfully, received a 

 prize from the French government for it, — a proceeding which 

 greatly disappointed Mr. Ritchie, who was entitled to it. The 

 improvement of Mr. Ritchie transformed the coil from being a toy 

 giving a two-inch spark to an instrument capable of giving a flash 

 two feet or more in length, and approaching the characteristics of 

 lightning. 



At the time of our Civil War Mr, Ritchie's attention was called to 

 the need of a better compass for our navy. The English Admiralty 

 Compass, considered the finest in the world, was in general use at that 

 time. In order to aid his study in making his improvements in this 

 instrument, he made a support so constructed as to give the motions 

 of a vessel at sea. 



After much thought and labor he invented the Monitor and Liquid 

 Compasses. The former did good service during the war, and the latter 

 was at once adopted by the Navy, and is now in use all over the world. 



He also constructed about that time another instrument which was 

 a great help to the Navy, the Theodolite, fastened to a pendulum hang- 

 ing in a tank of water, which enabled surveys to be taken of the harbors 

 on the Atlantic and Gulf coasts. For these inventions of high merit 

 he will be long remembered by the scientific world. 



He was an exceedingly conscientious man, and was ever ready to 

 help others over difficulties which he had overcome himself, and some- 

 times such persons received the credit and financial profit which rightly 

 belonged to him. 



He died on June 1, 1895, in his eighty-first year. 



1896. A. E. DOLBEAR. 



MARTIN BRIMMER. 



The various distinguished bodies to which our deceased associate, 

 Hon. Martin Brimmer, belonged, have already paid him such 

 varied and appreciative tributes that a detailed biography, in the 

 ordinary sense of the word, would be quite out of place. Nor was his 

 life itself so distinguished by striking adventures or significant dis- 



