1 
( 6 ) 
Fig. I. 
Jdiid reprefents a Lignum Vit^ Plug or Pifton (which 
Mr. Haskins call’d a Plunger^ about 6 Foot long made 
heavy enough with Lead at top to fink into Mercu- 
ry which is beforehand pour’d into the Barrel D i 
D 2 up to m m. The Chain E i E 2, joyn’d to the 
Pifton and the Power that moves it, being let down 
till the Pifton comes to D 2, the Mercury rifes to the 
fame Height in the Barrel, and in the Receiver K, 
(which it fills) namely to nn, as appears in the Fi- 
gure. Then drawing up the Pifton till its Bottom 
is come to mm^ the Mercurj coming out of the Re- 
ceiver down to makes a Vacuum^ and the Weight 
of the Atmofphere caufes the Water to rife up thro' 
the Sucking Pipe A i A 2, and Valve V into the 
Receiver where the Hercury was before. Upon let- 
ting down the Pifton again, the Mercury rifes into 
the Receiver, and drives up the Water thro’ the Elbow 
B, the forcing Valve //, and fo up the forcing Pipe 
4 2 4 1: But when once the forcing Pipe (which here 
was ^6 Foot high) is full, before any Mercury can en- 
ter into the Receiver, and force any Water out at the 
top of the Pipe 4 i, the Mercury between the Piflon 
and Barrel muft rife up to near 3 v Feet above the 
Bottom of the Receiver, and as it continues to rife 
up to pp, the Water is thrown out with a Velocity 
proportionable to the Freight that the Mercury is rais’d 
■above the i.:jtb part of the Height of the Water* 
Now tho’ the Fridion of Solids is here avoided, it 
is plain that the Mercury muft move from mm to qq 
without raifing any Water, and that it can only force 
in going from q q 10 pp, and only fuck in falling 
• from 0 0 to mmi And unlefs the Pifton is flopp’d a 
little. 
