Atkins, described in the Phil.
Charles's balance areometer is similar to Nicholson's hydrometer, except that the lower basin admits of inversion, thus enabling the instrument to be employed for solids lighter than water, the inverted basin serving the same purpose as the pointed screw in Atkins's modification of the instrument.
Atkins's hydrometer, as originally constructed, is described in Nicholson's Journal, 8vo, 276.
Further information concerning these instruments and the state of hydrometry in 1803 will be found in Atkins's pamphlet On the Relation between the Specific Gravities and the Strength of Spirituous Liquors (1803); or Phil.
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