( 8 ; 
Fig. lit. . 
Here the Barrel is mov’d as in Fig, 2, but the Plug 
ddd taking up a great deal of Space, there is Oc- 
cafion for no more Mercury than what will make a 
concave Cylinder or Shell up to pp between the Bar- 
rel D i D2, and the hanging Cylinder Ci Cz cc, 
when the Stroke is made for forcing ; and a concave 
Cylinder between the Plug and C i Cz cc, when the 
Sudion is made. I gave Mr. Haskins the Proportions 
for an Engine this way, of which he made a Draught, 
and fhew’d it to the Right Honourable the Lord Chan- 
cellour about fix Months ago. This I mention here, 
that no body may endeavour to get a Patent for this 
Invention, to the Prejudice of Mr. Haskins's Alfignees ; 
who, fince his Death, have defir’d me to affill: them in 
perfe(5ting the Engine. 
Fig; IV. 
Here the Barrel with a third Cylinder dddd in- 
Read of the Plug of Fig. 3, is 'lifted up and down 
every Stroke, and the Water pailes thro’ dddd, the Mer- 
cisry making a Shell, fometimes between the middle and 
inner Cylinder, as in the Sudion ; and fometimes be- 
tween the Barrel and the middle Cylinder, as in th.e 
forcing Stroke. 
Mr. Haskins had contriv’d fuch a Machine as is re- 
prefented by -this 4th Figure, and befpoke the feveral 
Parts before he dy’d ; and therefore when I was de- 
fir’d by his AfTignees to diredt the fetting up the Ma- 
chine, I was oblig’d to make ufe of the Pieces alrea- 
dy made, in order to fave the Expence of a new 
Engine: And now the whole put together with feme 
Al- 
