(445) 
loosened under decreased pressure, while to remove the glycerine 
one of the contacts is loosened a little under pressure. If the exact 
quantity of glycerine is present, and if during the exhaust the switch 
belonging to the contact C', is pressed down (§2 ©), the bell is 
not heard, if the same is done with the switch belonging to C’, the 
bell must always be heard, but with the switch belonging to C’, the 
bell is only heard for a moment. Pl. V fig. 2 shows a high-pressure- 
proof contact with platinum-point. 
(2. Up and down motion of the plunger. The plunger A’, together 
with the cross-arm 4’, (comp. also P]. II fig. 3) and the rod A 
which is directed upwards are forged of one piece of steel. The 
rod moves through a guide block Vs, (comp. § 2 5. 2) which con- 
sists of two parts Vs, and Voz screwed upon each other and is 
connected to the frame V, through the arm Voo. 
The lubricating oil which flows from the guide-block is caught 
in the cup 4’, which fits loosely on the cross-piece, and so cannot 
soil the glycerine (comp. § 2 4. 3). 
The side arms of the cross piece A's are moved up and down by 
drawing rods S,;. These are coupled to a ring Sg sliding round the 
smooth cylinder C’, (comp. §2 %. 2); the levers S; in moving up 
and down can turn on the bolts S,, with which they are fastened 
to the ring S3. 
The beam consists of two symmetrical curved levers being wider 
towards the side of the compression-tube, and enclosing it (comp. 
Fig. 3 Pl. IL and Pl. IV to the left, upper view of the ring), 
while the two parts where they are coupled to the connecting rod or 
with the hinge S, fit immediately against the smooth sides of the 
rods Sj. 
The piece Ss, consisting of the halves Ss; and S;, screwed against 
each other (comp. upper view Pl. IV) leaves room when moving up 
and down for the contact-screws C’; C',C';. For greater security it 
is covered with a small plate Sz, in which is a small lubrication- 
hole leading to the lubrication-canals $3; and S39. 
y. Transferring of the motion, gearing. In this connection 
fig. 1, 2 and 3, of Pl. IL must be consulted, on which no letters 
are placed for the sake of clearness. 
The connecting rod t, Pl. IV is moved by the crank U Uj, Urs 
on which is a ratchet wheel with ratchet and ratchetsupport to render 
a backward movement impossible. 
This improvement is especially useful when the pressure-valye 
