18 PROCEEDINGS OF THE NATIONAL MU8EVM. vol.49. 



fastened about the sides with ends for tying. Size, 9 by 7 inches. 

 Cat. No. 92614, U.S.N.M. 



Surveyor's compass. — Circular case of mahogany, bound with a 

 narrow strip of iron. Horizontal bar and standards of brass. Com- 

 pass face of highly polished metal marked with an eight-pointed star 

 indicating the cardinal and intermediate points, and covered with 

 glass top. Inscribed: "Rittenhouse, Philadelphia." * Used by Wash- 

 ington at Mount Vernon. Presented to the United States Govern- 

 ment by Anthony Kimmel. Deposited in the U. S. Patent Office, 

 and transferred to the U. S. National Museum in 1883. Diameter of 

 compass, 6^ inches; length of horizontal bar, 14 inches; height of 

 standards, G inches. Plate 23, Cat. No. 92538, U.S.N.M. 



Manuscript correspondence relating to compass. — Fourteen letters 

 written in 1851 and 1852 by Anthony Eammel, George Washington 

 Parke Custis, and others, concerning the surveyor's compass described 

 above. Bound together with a copy of the work by Henry T. Tuck- 

 erman, entitled "Character and Portraits of Washington," which was 

 published by J. Putnam, New York, in 1850. Inscribed in gold letters 

 on the cover, ''The Correspondence relating to the Sm'vcyor's Com- 

 pass of Gen. George Washington." Dimensions, 11 J by 9 by If 

 inches. Transferred from the U. S. Patent Office in 1883 to the 

 U. S. National Museum. Cat. No. 92542, U.S.N.M. 



Spyglass. — Tube, nine-sided, wound closely with a single thickness 

 of twine. Marked with the maker's name, ''Cole, Fleet Street, 

 London." Used by Washington at Momit Vernon largely for viewing 

 boats on the Potomac. Diameter of object lens, 2f inches; diameter 

 of eye lens, 1 inch; length, 63 inches. Lewis collection. Cat. 

 No. 92423, U.S.N.M. 



Field glass and case. — Brass tube, in three sections, with case of 

 russet leather. Used by Washington during the War of the Revolu- 

 tion. Diameter of object lens, IJ inches; diameter of eye lens, 

 1| inches; length, cIoschI, 9 inches; opened, 22;\- inches. Length of 

 case, 92 inches; diameter, 2^ inches. Lewis collection. Plate 24. 

 Cat. Nos. 92424-25, U.S.N.M." 



Portahle writing case. — Rectangular mahogany box, tlie lid covered 

 with black grained leather and lined with paper. Interior divided 

 into five compartments for paper, pens, pencils, and sealing wax. 

 Lid fitted with two brass hinges and a brass lock. To the side of the 

 case is affixed a large folding pocket of black grained leather for 

 stationery. Used by Washington during the War of the Revolution. 

 Presented to the Government in 1845 by Dr. Richard Blackburn. 

 Placed in the U. S. Patent Office, and in 1SS3 transferred to the U. S. 

 National Museum. Dimensions: 14 J by 14f by 3f inches. Plate 25. 

 Cat. No. 92529, U.S.N.M. 



> David Rittenhouse (1732-1796) was one of the mostnotedof American astronomers during the latter 

 half of the 18th century and manufactured mathematical instruments of exceptional accuracy. 



