| Description | Monthly meteorological data sheets, May-July 1841. Uncorrected meteorological observations, from the Niger Expedition of 1841, Form 2 only. Main table, containing columns of information on: date and Moon; barometer; temperature and dew point; wet bulb thermometer; temperature minimum and maximium, with solar radiation data; temperature of sea or running water; wind direction and gauge; rainfall; electricity; general weather remmarks; latutude and longitude at noon; with a repeated date and Moon column. A secondary table, below, is for uncorrected and corrected hourly observations of the barometer and thermometer on the 21st day of the month. This has been amended in manuscript [p.1] to '28th & 29th'.
The observations were commenced off Lisbon, Portugal and the ship's position is relayed by daily readings of latitude and longitude, interspersed with named locations, including: Santa Cruz, Teneriffe; Porto Grande St. Vincent's, Cape Verde; Sierra Leone; Liberia; Cape Coast Castle, Ghana [a 'slave castle']; and finally Accra, Ghana.
Not signed. Remarks on the monthly data for July [p.5] give further details of observational limitations and the lack of instruments, but include the name of the vessel: 'The Soudan not being supplied with a Dew Point Hygrometer...'. The sheets are endorsed verso: 'Niger Expedition'.
Each sheet is inscribed: 'Published by Richard & John E. Taylor, Red Lion Court, Fleet Street, London.'; and lower right: 'J. Basire sc.' One variant [p.1]: 'Sold by R.B. BATE, 21, Poultry'. |