2 7 



3. The teethwheels as made, caused such a noise that it was difficult to hear the 

 commands given. Accurately cut wheels with a true pitch with pinions of raw-hide might 

 improve this. 



4. The steel brake strap is too stiff, probably a strong leather one, also fitted on the 

 inside with wooden blocks, would do better. The objections to the present arrangement is as 

 follows. In order to let the line run out at a fairly high speed the strap must be loose. Now 

 if through a heave of the ship the tension of the line is slackened, but for an instant, the spiral 

 springs put the brake on. This is exactly what is intended, but the strap being so stiff it brakes 

 the machine so much that with the next heave of the ship in the opposite direction, the tension 

 in the line is suddenly too great. 



Of course the brake can be unscrewed, but the result is that the line does not run out 

 smoothly but with jerks. The scale also works jerky and may strike the stops, causing slack 

 in the line between the winding drum and the wiredrum. Owing to the former having more 

 momentum and maintain a more regular rate of revolution than the latter. It therefore gains 

 upon the winding drum, causing the brake to act too strong. 



5. The arrangement of the top- and outer guiding pulley does not offer sufficiënt security 

 against the danger of the line getting out and jamming between the sides of the pulley. This 

 could be improved by fitting proper guides, accurately fitting, round the edges of the pulleys. 



The cock-lead worked quite satisfactory. lts good and bad points in comparison with 

 others have already been mentioned. 



During the scientific expedition of H. M. Siboga 181 soundings were made with the 

 Le Blanc machine of which 129 were more than 2000 metres and 52 less. The greatest depth 

 reached was 56S4 metres. The machine worked well throughout, no defects of any importance 

 having taken place. The flanges of the smaller wire-reel were slightly strained and bent out, 

 this probably being caused by the tension of the wire being too great on hauling in, and could 

 easily be avoided. 



The screw of the adjusting friction-wheel was worn out. But it was found that a few 

 metres of wire could easily be hauled in without the use of this gear. The dynamometer soon 

 got out of order and even after being repaired was not improved. It was found that this type 

 of dynamometer was not proof against the shocks to which the ballastscale was exposed with 

 a pitching and heaving ship. 



It is however of so little practical use that it can safely be dispensed with, the loading 

 of the scale being a sufficiënt guide to find the average tension of the rope, always bearing 

 in mind that the scale itself weighed 18 kilogrammes and when in equilibrium the strain on 

 the rope is about half the combined weight of the scale and weights together. 



During the course of one year, from March ; lh 1899 to March i st 1900, when the 

 soundings above referred to, were made with this machine, the following list of accidents 

 occurred. 



