51 



Historical Society, September 27, 1848. 8vo. — From the Au- 

 thor. 



Journal of the Franklin Institute. Third Series. Vol. XVI. No. 6. 

 December, 1848. 8vo. — From the Institute. 



The Slave Question: Letter from Henry C. Carey, Esq., to Nathan 

 Appleton, Esq. January, 1849. 8vo. — Anonymous. 



The Medical News and Library. Vol. VII. No. 73. January, 1849. 

 Philadelphia. 8vo. — From Messrs. Lea ^ Blanchard. 



Letter from the Secretary of the Treasury, transmitting the Report 

 of the Superintendent of the Coast Survey. Presented to Con- 

 gress, December 18, 1848. Washington, 1848. — From Prof. 

 A. D. Bache, Superintendent of U. S. Coast Survey. 



Map of Delaware River and Bay; executed under the Direction of 

 the Coast Survey of the United States. — From the same. 



Prof. Frazer read to the Society the following letter from 

 Dr. Locke to Dr. Patterson, and exhibited a specimen of the 

 record made by the clock alluded to. 



Cincinnati, Dec. 30<A, 1848. 

 Dear Doctor, 



Every inventor is apt to become enamoured of his productions, and 

 not unfrequently obtrudes them unseasonably upon his friends. With 

 this view before me, it is not without some hesitation, that I enclose 

 to you a specimen of the performance of my telegraphic clock, which 

 I have invented upon the suggestion and solicitation of our able friend, 

 Sears C. Walker. You will see by the specimen, that the seconds 

 are marked by lines about half an inch long. The minute zero is 

 marked by the confluence of two lines, the break between two seconds 

 being omitted. The five minute signal is a dash, three seconds long, 

 occurring after the minute zero, but referring back to it. The hour 

 signal is a similar dash, occurring several seconds before the minute 

 zero, and referring also to it as the beginning of an hour. Observa- 

 tions are entered by breaking the circuit by means of a finger key, 

 under the hand of the observer. They come in in such a manner as 

 to indicate the exact fraction of the second, legible at least to hun- 

 dredths. But one clock is needed, and this will register its time at 

 any part of the circuit. Observers and keys may be stationed also 

 at any point in the circuit, and they are able to enter their observa- 

 tions on all the registers included in the line. Thus we have a very 

 faithful ubiquitary clerk, relieving the observer from every thing but 

 looking at the stars, and thumbing down his keys. 



