761 



which can be put in the required position by means of adjusting 

 screws. On the ph\te D an iron weight is placed, weighing with B, E, 

 F, and D together exactly 25 kg. Then plale-shaped weights of 25, 

 10 etc. to 1 kg. and lower are put on it with a slit, which enables 

 them to slide round the rod F. The whole apparatus is set rotating 

 by hand. 



For higher pressures the gauge cannot be worked solely by the 

 hand. The "head" of the pressure balance (the piece A with the 

 piston B, tig. 1) is mounted here on an iron stand 2 m. high, 

 which by accurate levelling has been adjusted, and rests on a 

 separate heavy stone foundation. Weights of 100 kg. lie round the 

 rod F (fig. 3) in rings, on which they rest. These rings are connected 

 by means of two bars G and the distances between the rino-s are 

 taken so that between two weights there always remains a space 

 of 2 cm. 



The rods Q are provided at their upper ends with screw thread, 

 and are in this way carried by the nuts H (fig. Za) ^), which rest 

 on the top plate of the iron stand, and are fixed by bent pieces L. 

 The nuts H are provided on the outside with teeth, in which a 

 worm K catches. By means of this the nuts H can be turned, and 

 in this way the rods G and all the rings attached to them can be 

 adjusted higher or lower. When the rods are turned down, first the 

 lowest weight will get to lie on the plate D, this weight has been 

 taken so that together with the plate D, the rods F and E, and 

 the piston it weighs exactly 100 kg. If the rods G are turned still 

 lower down, another weight of exactly 100 kg. will rest on this 

 weight etc. In this way the pi&ton can in all be loaded with 1150kg. 

 If the worm is turned in the opposite direction, the rijig-system rises, 

 and lifts up the weights one after another, which relieves D. By 

 means of a transmission with two loose pulleys and a fast pulley 

 the worm is driven from a siiaft, which in its turn is set going by 

 an electromotor of J H.P. Two belts run over the loose pulleys, a 

 crossed one and a straight one. By a simple adjusting apparatus 

 either the one or the other can be transferred to the inteijacent fast 

 pulley, by which weights are put on or taken off. Smaller weights are put 

 on by the hand on the plate D' , which is fastened on the rod F. 



In the second place it is necessary to get a mechanical arrange- 

 ment to set the pressure balance rotating. For this purpose a toothed 

 wheel M "*) (Fig. 3/;) has been fixed on the rod F, which engages 



1) Fig. 3a gives a view from below, omitting llie plate on which everything 

 rests, hi Fig. 3 the nuts H are hidden behind the worm K and the rod on which 

 it is fastened. 



2) In Fig. 3 M is hidden behind N. 



49* 



