250 J. Locke on the Electro- Chronograph. 



still further, and invented the electro-chronograph which superse- 

 ded entirely, the plans primarily suggested to me. This inven- 

 tion was exclusively my own, and when it was communicated to 

 Mr. Walker and to Dr. Bache, they both expressed their agreeable 

 surprise ; nor was it without some great effort that I made my 

 plans intelligibly understood. It could not for example at first be 

 seen that only one clock was necessary in the operation. Nor has 

 the very basis of the whole affair, the closed circuit, been practi- 

 cally understood up to this moment. Mr. Walker never intended 

 such a meaning as has been attached to the passage, for that 

 meaning is inconsistent with truth, and with his previous state- 

 ments. 



28. " The mode of using the register for marking the date of 

 any event that cannot be determined automatically, but whose 

 occurrence must be known from human sensations, is to tap on a 

 break circuit key simultaneously with the event. The beginning 

 of the short blank space thus registered in the midst of the in- 

 dented line of the automatic clock register, fixes, by a permanent 

 printed record, the date of the event, or rather the date of the 

 human estimate of the event, as indicated by the tap of the key. 



"For this mode of distinguishing the hours, minutes and sec- 

 onds on the fillet of paper, and for the idea of using the break 

 circuit key, I was indebted to Doctor Locke. This kind of key 

 is required by the necessity of having a closed circuit for the reg- 

 ister as much of the time as possible, so that an event occurring 



any where along the line may be instantly recorded on the reg- 

 ister." 



In the second paragraph, " For this mode," &c, instead of be- 

 ing credited with f the whole combination of the " Printing Meth- 

 od" both generally and in detail — I am represented as furnishing 

 piece work for a master. Mr. Walker acknowledged himself in- 

 debted to me for a " break circuit key" ! and a mere " tilt ham- 

 mer" interruptor I suppose. So inconsistent are these expressions 

 with the frank communication of the same author to the U. S. 

 Gazette, already cited, that I will not attribute them to him, but 

 to some Mentor especially solicitous that Dr. Locke and his in- 

 vention should not be "praised too much." 



The author closes his paragraph by a very proper allusion to 

 the necessity of a " closed circuit" as pointed out in my letter to 

 Dr. Bache, but he has every where practically disregarded that 

 principle by citing machines which do not fulfill that condition, 

 as the equivalents of my own. 



29. "The great importance of an automatic telegraph clock 

 has often been the subject of conversation between us, but your 

 chief efforts were, necessarily, directed at first to the means of 

 procuring it. A hasty glance at the advantages that would result 

 from the certain possession of such an instrument, was made by 



