

/. Locke on the Electro-Chronograph. 247 



21. It seems that his report has been rendered obscure and am- 

 biguous, by the introduction of a new coined word, borrowed in 

 part at least from an expression in my letter to the Gazette, 

 where I name my invention the "Automatic Clock." But Mr. 

 Walker has used the term ' k automatic clock register/' not ex- 

 actly in the sense in which I used the first part of the phrase, 

 nor has he used it in a uniform sense as is evident from his 

 context. It was well perhaps, as a matter of taste, to avoid 

 the too frequent introduction of my own name, but when my in- 

 vention is so often called the " Automatic clock Register" some 

 more intelligible phrase would certainly have been preferable. I 

 have not a copy of your Journal before me, and I therefore quote 

 from the original document as published by Congress. 



22. The following is Mr. Walker's introduction, p. 2, Doc. 21. 



"Washington, D. C, December 15, 1848. 



" Dear Sir : I beg to call your attention to the importance of 

 the use of an electro-magnetic circuit and an astronomical clock 

 in connexion with Morse's telegraph register for the operations of 

 the coast survey, and the general purposes of practical astronomy. 

 Your thoughts having been first turned to the subject of the use 

 of Morse's electro-magnetic telegraph in the longitude operations 

 of the coast survey, in December, 1844, special instructions were 

 issued to me in the autumn of 1845. Under these and subse- 

 quent instructions, the operations of 1846, '47 and '48, entrusted 

 to my care, have, until near the close of the latter year, been con- 

 ducted without the use of the automatic clock register. 



" The importance of the latter instrument induced you to direct 

 the necessary researches to be instituted, for the purpose of intro- 

 ducing it into use in the coast survey service. Several methods 

 have been suggested by eminent mechanicians and electro-mag- 

 netists. That of Mr. Wheatstone is briefly alluded to in the 

 proceedings of the Royal Astronomical Society, for 1841, Novem- 

 ber 19th. The galvanic circuit in his clock, is made and broken 

 by the use of a circular metallic disk, put on to the arbor of the 

 seconds' hand. Alternate intervals of a second, or one-sixtieth 

 of the circumference, are made of a non-conducting substance. 

 The disk is insulated and connected with one pole of a galvanic 

 battery. A delicate spring connected with the other pole presses 

 gently on this disk. Thus the circuit is made and broken at al- 

 ternate seconds. This mode enables the primitive clock to con- 

 trol the motion of any number of clocks in connexion with it 

 Every time the circuit is broken or made, any receiving clock- 

 wheel with sixty teeth may be made to advance one second, and 

 this wheel may in the usual way control the minute and hour 

 wheel." 



As Mr. Walker uses the term " Automatic clock Register" in 

 the following part of his report to signify the "Printing Method" 



