1 82 NATIONAL ACADEMY OF SCIENCES 



ment was exhibited at the meeting of the British Association in 

 1833. "The poet Coleridge, who was present at its exhibition 

 in Cambridge, spoke with enthusiasm, not only of the magnitude 

 of the discovery of the inductive electrical effects of magnetism, 

 one of the claims of Faraday to imperishable reputation but 

 also of the ingenious invention of Mr. Saxton, by which the 

 transient electrical currents might exhibit their effects in so 

 brilliant and so powerful a manner." (Henry.) 



Saxton produced many other inventions while in London, 

 among them a locomotive differential pulley, an instrument to 

 measure the velocity of vessels, another for measuring the height 

 of water in a steam boiler, a fountain pen, etc. He also devised 

 a method for locating the interior magnetic poles of the earth, 

 and constructed the apparatus used by Wheatstone to measure 

 the velocity of electricity in a long wire. 



Leaving London in 1837, he was appointed constructor and 

 curator of the standard weighing apparatus in the Mint at 

 Philadelphia. While here his improved form of Gobrecht's 

 instrument for reproducing the designs of medals by engraving 

 was brought into use. He also constructed balances for weighing 

 coins, of such delicacy that they would turn with one three- 

 millionth part of their load. 



In 1834 Saxton was awarded the Scott Medal of the Franklin 

 Institute for the invention of a reflecting pyrometer, an instru- 

 ment which was capable of indicating changes in the length of 

 a metal bar to the one-hundred-thousandth part of an inch. 



In 1843 Saxton was appointed by Professor Bache to take 

 charge of the construction of the standard balances, weights and 

 measures which were authorized by Congress for distribution 

 to the several States of the Union. While in this position he also 

 devised many instruments for use in the Coast Survey, including 

 an automatic instrument for recording the height of tides, and an 

 improved automatic dividing machine. 



At the meeting of the American Association for the Advance- 

 ment of Science in 1858, Saxton gave an account of the use of the 

 revolving mirror in minute measurements, such as the expansion 



