Chapter Prompt-book to Proofless of P by Webster's Dictionary (1913 Edition)

specific gravity 0.7939 referred to water at its maximum density as unity. Proof spirit has at 60° Fahrenheit a specific gravity of 0.93353, 100 parts by volume of the same consisting of 50 parts of absolute alcohol and 53.71 parts of water," the apparent excess of water being due to contraction of the liquids on mixture. In England proof spirit is defined by Act 58, George III., to be such as shall at a temperature of 51° Fahrenheit weigh exactly the ½x13 part of an equal measure of distilled water. This contains 49.3 per cent by weight, or 57.09 by volume, of alcohol. Stronger spirits, as those of about 60, 70, and 80 per cent of alcohol, are sometimes called second, third, and fourth proof spirits respectively. —

Proof staff, a straight-edge used by millers to test the flatness of a stone. — Proof stick (Sugar Manuf.), a rod in the side of a vacuum pan, for testing the consistency of the sirup. — Proof text, a passage of Scripture used to prove a doctrine.

Proof-arm
(Proof`-arm") v. t. To arm with proof armor; to arm securely; as, to proof-arm herself. [R.] Beau. & Fl.

Proofless
(Proof"less), a. Wanting sufficient evidence to induce belief; not proved. Boyle. — Proof"less*ly, adv.