DEEP-SEA EXPLORATION. 
319 
ill tends to draw the pulley dowu so near the reel that it is difficult and at times 
impossible to guide it evenly upon the drum ; heuee the necessity for a simple method 
of suspending tlie pulley at the top of the frame, at tlie same time retaining the 
dynamometer, or adopting another by which the strain on the wire may be noted. 
The dynamometer stall' is a brass tube of commercial pattern, cut to the desired 
length, and an eye of cast brass seenred in its upper end. At the lower extremity is 
a spiral compression spring of phos[)hor bronze. If inches in diameter and 8 inches 
long, held in ]>lace by a small shoulder and drift i>iu. 
To use it, the sinker having been detached, place the spiral spring over the top of 
the s])iir buffer, lift the pulley to the top of the frame, and secure the eye of the stall' 
in the socket at the lower extremity of the crosshead frame by a loose pin provided 
for the puiT)Ose. With the pulley in this position, the wire is guided upon the reel 
with the minimum of exertion and friction, and the elastic limit of the spring, about4 
inches, being divided off as a scale on the left accumulator tube, the strain put upon 
the wire is under the constant observation of the operator. 
The scale is marked from 100 to 130 pounds, the tension being obtained by clapping 
a spring scale on the end of the stray line, and with a piece of chalk marking the lines 
as desired ; it is the work of a moment and preferred to a permanent scale, whicli would 
require frequent verification. Either arm of the crosshead may be used as a pointer, 
but the lower one, being nearly on a level with the eye, is preferable. 
The adoi)tion of the staff interfei ed with the use of the main accumulator while 
reeling in, but the machine being located at the stern and the vessel steaming ahead 
there was no fear of fouling, and the danger from jerking strains in a seaway being 
much reduced by the trend of the wire astern no inconvenience was suffered from 
the new arrangement. The speed of the reel was governed entirely by the strain 
upon the wire; 110 pounds 
was considered thoroughly 
safe practice, 120 pounds 
was the ordinary working 
strain, and 130 pounds the 
. 1 - -i, X- X- X Cut 44. — Guide for temperature wire, 
extreme limit ot safety, 
which was not exceeded under any circumstances. With the introduction of the 
dynamometer staff the speed of the reeling engine was increased, the danger from 
slack turns on the drum disappeared, and a noticeable decrease was observed in losses 
from defective splices. 
The (juide for the temperature tvire, as improvised by the writer in 1891 and first 
used aboard the Albatross on the cable survey between California and the Sandwich 
Islands, has an oak frame in which is a long slot carrying a pair of brass rollers, 
lashings being provided at each end for convenience in securing it in place. To 
prepare it for use, remove the fair-leader and swivel pulley from the sounding machine, 
ship the dynamometer staff, lash one end of the guide to it just below the accumulator 
pulley, securing the other wherever most convenient; then, having mounted the reel 
containing the temperature wire, run the stray line over the pulley and between the 
rollers on the guide and bend on the sinker. 
With this arrangement of guide, thermometers and water bottles are fastened to 
the wire and removed from it at a convenient height above the grating, which is a 
convenience at all times, and iiarticularly so in heavy weathei'. 
