Cragg, William, fl1818 - 1828 (petitioner to the Board of Longitude)
Found in 9 Collections and/or Records:
Letter from William Cragg to Andrew Aiken, 1819-06-16
Eight letters from Cragg concerning his proposal for finding longitude by a ship's reckoning using a compass and charts, without the assistance of celestial lights or books of calculation. Includes charts for sailing [RGO 14/39: 53] and [RGO 14/39: 68v].
Letter from William Cragg to Andrew Aiken, 1819-07-26
Concerning longitude and enclosing a chart.
Letter from William Cragg to [Andrew Aiken], 1820-04-27
Concerning his theories on finding longitude.
Letter from William Cragg to Dr Thomas Young, 1820-08-12
Originally enclosing papers on finding longitude.
Letter from William Cragg to Dr Thomas Young, 1821-09-06
Outlining his proposals for finding longitude and enclosing a chart.
Note: folios 67-69 were originally bound in the wrong order and should be read 69, 67-68.
Letter from William Cragg to Dr Thomas Young, 1828-05-20
Proposing the use of a mechanical apparatus which could be 'affixed' to a ship to measure its progress, with the distance travelled then used to determine longitude.
Letter from William Cragg to Lord Melville, 1818-08-10
Includes a chart to work out latitude or longitude at sea from any place.
Letter from William Cragg to the Board of Longitude, 1821-09-07
Requesting permission to use the observatory at Greenwich.
William Cragg on the cause of the variation of the magnetic needle, 1825 - 1828
Correspondence regarding the effect of magnetic variation on the mariner's compass, the use of magnetic variation to establish longitude and the cause of magnetic variation.