areometers

Upon those principles are made two kinds of areometers -- one for fluids denser than water; the other for those that are lighter: the first are called _salt proof_; the second _spirit proof_.

The Art of Making Whiskey So As to Obtain a Better, Purer, Cheaper and Greater Quantity of Spirit, From a Given Quantity of Grain

It is capable also of replacing areometers in ordinary determinations, since it permits of correcting the error in capillarity that is neglected in instruments; and, moreover, one can, when he desires to, easily verify for himself the accuracy of the graduation.

Scientific American Supplement, No. 561, October 2, 1886