The Atmospheric Tide is uniform, as to time, at all elevations; but <lb xmlns="http://www.tei-c.org/ns/1.0" />the amount gradually diminishes, & progressively with the elevation; <lb xmlns="http://www.tei-c.org/ns/1.0" />– at <measure xmlns="http://www.tei-c.org/ns/1.0" quantity="17000" unit="foot">17,000 feet</measure> it appears to be but a few thousandths of an <measure xmlns="http://www.tei-c.org/ns/1.0" quantity="1" unit="zoll_englisch">inch</measure>. <lb xmlns="http://www.tei-c.org/ns/1.0" />I almost invariably read off all the Instruments 7 times in the 24 <lb xmlns="http://www.tei-c.org/ns/1.0" />hours; & I have horary observations, from all heights, up to <measure xmlns="http://www.tei-c.org/ns/1.0" quantity="16000" unit="foot">16,000 <choice> <abbr>ft</abbr> <expan>feet</expan> </choice></measure>. – <lb xmlns="http://www.tei-c.org/ns/1.0" />I take the same times as at the <placeName xmlns="http://www.tei-c.org/ns/1.0" ref="https://edition-humboldt.de/H0016218 https://www.geonames.org/1275004">Calcutta</placeName> Observatory.