COMMITTEES ON BEHALF OF THE GOVERNMENT 241 
terms “ above proof” and “ below proof’; that a special form 
of hydrometer designed by Wm. G. Tagliabue of New York, 
be used instead of the ordinary Tralles instrument, and that 
the Government should test these hydrometers and issue them to 
the inspectors free of expense. The hydrometers, which were 
figured in the report of the committee, were to be made in series 
of five each, so graduated as to cover all percentages from pure 
alcohol to pure water. The tables which accompanied the report 
cover 25 pages. They give real and apparent specific gravities 
and percentages for all mixtures of alcohol and water at different 
temperatures from zero to 100° Fahrenheit, together with other 
data of similar character. In addition, the report has appended 
to it a ‘““ Manual for inspectors of spirits,” consisting of tables 
showing the true percentage of proof spirits for and indication 
of the hydrometer at temperature between o° and 100° F., and 
instructions for their use. This part of the report covers thirty- 
four pages. 
The committee was not content to restrict its tables to the 
temperature limits of the earlier ones, but carried on an elaborate 
series of experiments to ascertain the proper readings of hydrom- 
eters at temperatures as low as zero Fahrenheit. This was neces- 
sitated by the fact that spirits were sometimes received at ware- 
houses in the Northern States in winter time at temperatures far 
below freezing and often approaching the zero of the Fahrenheit 
scale. These experiments were carried on, by request of the 
Treasury Department, at the laboratory of the Surgeon-Gen- 
eral’s Office, and were conducted by Dr. B. F. Craig. 
The committee also considered various forms of hydrometers 
and decided to recommend one which, in its opinion, was best 
adapted for the revenue service. Dr. John Torrey and Dr. 
F. A. P. Barnard made especially accurate mixtures of water 
and alcohol and prepared and marked a series of delicate floats 
which were afterwards used by Tagliabue in graduating the 
hydrometers which he manufactured for the Treasury Depart- 
ment. 
