_Equal Altitude Telescope_ of brass, 17 in. long, on wooden tripod about 46 in. high. Objective lens is missing. Signed "Henry Voigt." Made about 1790 and used for determining meridian lines and time observation of the sun's noon transit. This form of instrument was originally invented about 1716 by Roger Cotes, professor of astronomy at Cambridge, as a simple instrument for the determination of time. Deposited in the U.S. National Museum by the Smithsonian Institution in 1939. USNM 311772. FIGURE 31. WASHINGTON, GENERAL GEORGE (1732-1799), Mount Vernon, Va. _Compass Sundial_ described by the donor as having been presented to Gen. George Washington by General Braddock on the retreat through Paris Gap, Fairfax County, Va. Gift of Samuel Keese in 1902. USNM 9842. _Field Glass_, brass tube in three sections, length closed 9 in., opened 22-1/2 in. Diameter of object lens 1-3/4 in., of ocular lens 1-1/8 in. With original case of russet leather, which is 9-1/2 in. long and 2-1/2 in. in diameter. Maker not known. Stated to have been used by Washington during the Revolutionary War at the campaign of Valley Forge. According to related correspondence, when not in use the instrument was carried by the General's body servant, Billy Lee. The General presented the field glass to Major Lawrence Lewis, his favorite nephew, in 1799, the last year of his life. Purchased by the U.S. Government from the Lewis heirs in 1878 and transferred to the U.S. National Museum in 1883. USNM 92424, 92425. FIGURE 82. _Spyglass or Telescope_, made of wood, 9-sided, wrapped throughout with twine, 62 in. long. Brass mountings for object and ocular lenses made by "Cole, Fleet Street, London." Diameter of object lens 2-3/4 in., diameter of ocular lens 1 in. [Illustration: Figure 82.--Brass field glass in case of russet leather, stated to have been used by General George Washington at Valley Forge. USNM 92424, 92425.] The maker, Benjamin Cole (1725-1813), was the third generation of instrument makers of the same name. Other instruments by this maker are in the National Maritime Museum and the Whipple Museum, Cambridge. [Illustration: Figure 83.--Telescope, 62 in. long, made of wood wrapped with twine. It was made by Benjamin Cole of London and was owned and used by Gen. George Washington at Mount Vernon. USNM 92423.] This telescope, used by General Washington at Mount Vernon, "was kept behind the hall door and his favorite amusement was to look out over the river with it." According to Mrs. Lewis, the General used it to observe life on the river and especially to discover guests approaching Mount Vernon, as many of their visitors arrived by boat. Benjamin Latrobe, the architect, on a visit to Mount Vernon made an amusing sketch of his host looking anxiously up the stream for some belated dinner guests. Part of the collection purchased from the Lewis heirs in 1878 by the U.S. Government and transferred to the U.S. National Museum in 1883. USNM 92423. FIGURE 83.