312 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
give a very rapid descent — a descent so rapid that in the course of half an hour or fifty minutes the 
hottom will be reached at a depth of 2,000 or 3,000 fathoms. The person in charge watches a counter, 
and for every 250 fathoms (that is, every 250 turns of the wheel) he adds such weight to the hreak-cord 
as shall add 3 pounds to the force with which the sounding wheel resists the egress of the wire. 
That makes 12 ]iomids added to the break resistance for every 1,000 fathoms of wire run out. The 
weight of every 1,000 fathoms of the wire in the air is 14-J^ pounds. In water, therefore, the weight is 
about 12 pounds; so that if the weight is added at the rate I have indicated the rule stated will be 
i'nlfilled. So it is arranged that when the 34-pound weight reaches the bottom, instead of there being 
a pull or a moving force of 24 pounds on the wire tending to draw it through the water, there will 
suddenly come to be a resistance of 10 pounds against its motion. A slight running on of the wheel — 
one turn at the most — and the motion is stopped. 
The sounding was made without a hitch of any kind, but the reel showed signs of 
weakness soon after he began reeling in the wire and the 34-ponnd weight of sinker, 
which is referred to by Sir William as follows: 
After a.bout 1,000 fathoms of wire had been got in the wheel began to show signs of distress. I 
then perceived for the first time (and I felt mmdi ashamed that I had not ])erceiveil it sooner) that 
every turn of wire under a pull of 50 pounds must press the wheel on the two sides of any diameter 
with opposing forces of 100 pounds, and that, therefore, 2,240 turns, with an average pull on the wire 
of 50 pounds, must press the wheel together with a force of 100 tons or else something must give way. 
In fact, the wheel did give way, and its yielding went on to such an extent that when 500 fathoms of 
wire were still out the endless cord which had Ijeen used for hauling would no longer work on its 
groove. 
Sir William realized tlie necessity for ini])rovement and encouraged inventors to 
take it in band. Captain Belknap, U. S. N., was the first to use it, practically, and 
he soon remedied its greatest fault by devising a reel capable of withstanding the 
enormous crushing strains incident to actual service. He was very careful at first 
about increasing the weight of reel, lest its greater inertia should destroy its useful- 
ness, but he soon found that a few pounds more or less was a matter of indifference 
to the practiced marine surveyor. Imiu'ovements have been introduced from time to 
time in this and other countries, but the princiiile of the Thomson machine is invari- 
ably retained. 
THE SIGSBEE MACHINE FOR SOUNDING WITH WIRE, AND ITS ACCESSORIES, 
AS USED ON BOARD THE ALBATROSS. 
This admirable machine was constructed by Mr. D. Ballauf, Washington, D. C., 
under the personal supervision of the inventor. Commander C, D, Sigsbee, U. S. N., 
and is still in good condition after constant service of fourteen years. A few improve- 
ments have been added from time to time, yet it remains essentially the same as when 
received from the hands of the maker. 
The aim of the inventor was to design a machine that should be light, strong, 
simple in structure, easily manipulated, and accessible in all its parts, yet compact 
and susceptible of snug stowage when not in use; hence steel was used whenever 
in acticable, and brass was utilized for the minor parts where immunity from oxidation 
was of more importance than great strength. 
It is secured to an iron bedplate by the clamps/ and compressor c/ (plate xix), 
and projects over the stern e sufficiently to allow the wire a clear passage from the 
machine to the water when rigged out for service, and is entirely within the line of the 
stern when rigged in. The wooden frame d surrounds the Sigsbee machine and 
supports the working platform and the Tanner machine. The ])latform consists of 
