Examples from the Web for tw
The cotton is first steeped in a bath of acetate of lead of about 10° Tw.
The souring is done by passing the goods through an acid liquor at 2° Tw.
The chemicing is best done cold and with weak solution, at ½° Tw.
This is made as follows: a soda ash liquor of about 15° to 20° Tw.
The concentration may be performed in two stages—first to a density of 32° Tw.The Handbook of Soap Manufacture
W. H. Simmons