40(j 
BULLETIN OF THE UNITED STATES PlSH COMMISSION. 
THE METRIC SYSTEM. 
The metric system is in general use by naturalists for the measurement 
of lish and other forms. A meter is the standard of linear measure. It is 
the ten-millionth part of a (luadrant of the meridian, or 39.-370 inches. A 
meter equals 10 decimeters, 100 centimeters, and 1,000 millimeters. 
The accompanying scale of English inches and millimeters furnishes 
a convenient method of comparison and conversion, one into the other. 
GENERAL REMARKS ON PRESERVATION OF SPECIMENS. 
The data from which the following description of the methods of 
preserving specimens obtained by the collecting apparatus is compiled 
Avere kindly furnished by Messrs. James E. Benedict, of the Smithsonian 
Institution, and C. II. Townsend, resident naturalist of the Albatross. I 
have also quoted freely from Bulletin No. 39 of the National Museum. 
The chief object of the deep-sea investigator is to obtain accurate 
information regarding life in the waters of the ocean and the physical 
conditions under which it exists, rather than the discovery of new and 
wonderful forms, each successful haul of trawl or dredge being made to 
do its part. 
In oi)erating the collecting apparatus and before it reaches the 
surl'ace, the oflicers of the ship have given the station a serial number, 
located it astronomically, ami recorded its physical conditions, the depth 
of water, character of the bottom, temperature of the air, surface, and 
bottom, specific gravity, currents, etc., and when the specimens are identi- 
fied and described their names will ever after be linked with that iiarticular 
station. Hence one’s best work, or that of other investigators, will be dis- 
credited or worse by carelessness on the part of those having charge of 
the handling and ])reservation of specimens. A label giving a wrong 
station number, a traAvl net not Avell shaken out and picked over, speci- 
mens carelessly left in the corners of the table sieve or on deck, where 
they may become mixed with the contents of a subsequent haul at another 
station, will falsify the record, perchance beyond the iiossibility of correc- 
tion. If there is a doubt as to the station to which a specimen belongs, 
give it the date and any other available inforination, but no attemi)t should 
be made to supply a station number by guesswork. No label at all is 
better than a false record. 
The contents of the trawl having been landed in the table sieve 
(plate xxxiv), the net should be carefully examined for hydroids, corals, 
or other delicate forms that are often found entangled in the meshes, cling- 
ing to the web, or caught on the frame, and in this seemingly accidental 
way valuable specimens may be taken in good condition that would be 
liable to serious damage if imbedded in the mud and general contents 
of a haul. 
The fish found in the table sieve are picked out and placed in buckets 
or tubs of clean water; the invertebrates are assorted in a general way 
into pans, di.shes, or sieves; the deck hose, without nozzle, is used to wash 
JT <D.-^omparat,.vc sc.ale of line.av mud through the grated bottom of the table sieve, 
measure, inches ami millimeters. care being taken not to injure the specimens. It is 
