July 19, 1820. | Meridian double altitude of Antares | 51° 36´ 00˝ | Index error--3´ 22˝. Latitude } | | deduced } | 38 14 18 N. +-------------------------------------+--------------- _Camp on the Arkansa, at the place where the Exploring Party was divided into two detachments._ _Equal altitudes of Sun to find error of watch, at midnight._ | Time before | Time after | Error of Watch. | Midnight | Midnight | ---------------+-----------------+-------------------+----------------- July 21, 1820. | 8ʰ 39´ 58˝ | 8ʰ 17´ 50˝ }| 17´ 19˝ slow. | 8 38 38 | 8 16 30 }| Mean time. | 8 37 18 | 8 15 1 }| +-----------------+-------------------+----------------- _A mean of eight lunar distances and times correspondent,--nearest limb of moon from star Spicæ Virginis._ | Time per Watch | Distance of Moon | Index error. | P.M. | and Star. | ---------------+-----------------+-------------------+--------------- July 21, 1820. | 9ʰ 40´ 54˝ | 51° 45´ 47˝ | - 3´ 30˝ +-----------------+-------------------+--------------- Variation of watch 47˝ per 12 hours losing. Error of watch to be estimated. Longitude by account 6ʰ 58´ W. Lat. determined by subsequent observations. Longitude of Camp, 6ʰ 55´ 05˝ or 103° 46´ 15˝ W. of Greenwich. _Equal altitudes of Sun to find error of watch, at noon._ | Time from Noon, | Time from Noon, | Error of Watch. | A.M. | P.M. | +-------------------+-------------------+----------------- July 22, 1820.| 2ʰ 58´ 21˝ | 2ʰ 34´ 09˝ } | 18´ 06˝ slow. | 2 56 59 | 2 32 47 } | Mean time. | 2 55 36 | 2 31 23 } | +-------------------+-------------------+----------------- July 22, 1820.| Meridian double altitude of Antares | 51° 40´ | +----------------- | Index error--3´ 30˝. Latitude } | | deduced } | 38 12 22 N. --------------+---------------------------------------+----------------- {xl} _Camp on the Canadian River of August 6th._