3i 



If not carefully regulated, the drum unwinds at such a rate that the wire, especially 

 with a rolling or pitching ship, looses too much of its tension, this allows the lever to rise and 

 tighten the brake, causing a sudden decrease in the veering of the rope, consequently the strain 

 on the rope increases and the brake is slackened again. This goes on repeatedly causing the 

 lever to rise and fall to no good. 



The tension of the spiral springs and correct adjustment of the sliding-block is found 

 by experience, taking in consideration the type of sounding lead in use and the amount of wire out. 



The adjustment of the brake-belt can remain unaltered for a considerable time. 



Any kind of lead can be used with this machine but as the hauling in is done by hand, 

 it is desciable to have the lead not heavier than absolutely necessary. 



On board of H. M. Siboga we always successfully used an ordinary lead weighing 12 

 kilogram, fitted with grease, occasionally also a light sliplead. As the indicator registers the 

 amount of rope out, the line should hang as nearly as possible vertical during the sounding. 



With regard to the measures to be taken and the manoeuvring of the ship, the same 

 remarks apply as those given for the Le Blanc-machine, also to the keeping in repair of the 

 machine and wire. A loose wooden cover over the machine was found to be a great help to 

 its preservation. 



Observations on the machine. 



The small size Lucas-machine gave every satisfaction. 



It was used both on board the ship and in the boats and was fixed to the end of a 

 board which facilitated its being placed in position where ever it was wanted. Its usual place 

 was on the starboardside of the bridge, the board being fastened to the railing and the machine 

 projecting as far overboard as would insure a vertical drop, well free of the ship. 



A sounding of a hundred fathoms took about five minutes: 50 seconds for dropping the 

 lead and 4 minutes for hauling it in. 



No other accidents occurred than once when the lead jammed and bent the plate-iron 

 lever, breaking the line. This mishap can be avoided by making the stray line no stronger 

 than is necessary to carry the lead safely and raise it from the ground. 



It is also advisable to provide the handles on the shaft with setscrews as it happened 

 that one handle was lost by dropping off. 



This machine can be highly recommended for hydrographic work as the sounding, both 

 at moderate and at great depth, is done more vertically and more accurately than with an 

 ordinary sounding line. 



For ordinary navigation it is inferior to the Thompson-machine as it requires the ship 

 to be almost at rest during sounding. 



For the vessels in the hydrographic service the small size Lucas machine is the 

 proper instrument for all soundings over 20 fathoms, for shallower depths the ordinary hand 

 lead is to be preferred as it can be thrown forward and does not require the same reduction 

 in speed as the automatic machine. If the depth is approximately known and not very great, 



