154 PROCEEDINGS OF [Feb. 



First and Second Book of Natural History, by W. S. W. Ruschen- 



berger, Surgeon U. S. Navy. — From the Author. 

 History of the Bible, (in Chinese characters.) — From Geo. Fuller. 



The Corresponding Secretary reported the following lettere and 

 communications. 



From Henry J. Rogers, of Baltimore : 



Baltimore, January 10, 1842. 



Sir : I have the honor to present for consideration before the " National Insti- 

 tution for the Promotion of Science," the model of a Land and Marine Telegraph, 

 of which I am the inventor. , 



For land operations, its simplicity may recommend it to favorable notice. 



For sea service, it has been pronounced by several nautical gentlemen as being 

 better adapted than any other system of telegraph now in use, as the signals are 

 m&de with the same means on land or afloat. 



The nature of my invention for sea service, consists in the application of balls, 

 by being placed opposite to corresponding balls, which are attached to cordage at 

 equal distances apart. 



For land service, five circular boards of equal diameter, and of equal distance 

 apart, attached to fi perpendicular staff of suflBcient size and elevation, with four 

 or more additional balls raised by chains opposite to the circular boards or nume- 

 rators. 



I will proceed to describe its construction and operation for land service, which 

 is as follows : I construct in the first place, a stafi" or mast sixty feet in height ; 

 which has attached to it, at the distance of twenty-Uiree feet above the earth, a 

 circular board of three feet diameter, and at intervals of three feet, I place four 

 more circular boards or numerators. 



The circular boards and interstices, I term numerators; the first circular board 

 I count as one, the second as three, the third as five, the fourth as seven, and the 

 fifth as nine ; also, I count the first interstice as two, the second as four, the third 

 as eight, and the fifth as ten ; each of which being counted, numbers 1, 2, 3, 4, 5, 

 6, 7, 8, 9, 10. 



The circular boards of three feet diameter being placed at intervals of three feet 

 apart on the perpendicular staff, and facing the observer, can be seen at a great dis. 

 tance, and are easily distinguished from the interstices. I also use a horizontal 

 yard-arm, which is attached at the centre horizontally to the staff, and six feet 

 above the highest circular board, on which yard there is attached a board of a 

 quarter of a circle, one of a semi-circle, and one of a segment or Ihree-fourths of a 

 circle, which I designate as markers. The last mentioned is placed on one end of 

 the arm, presenting the same face as the circular boards, the next at a distance of 

 four and a half or five feet, the other is placed five feet from the opposite end of the 

 yard arm, to which there is a block ; and to cacli of the markers I have a block, 

 through which blocks pass light chains, and these chains run to windlasses within 

 the "telegraph house," for the purpose of elevating the balls termed denominators, 

 attached to the chains. 



