C M° 1 
wards the proving the Weight of the Atmofphere by 
which the Mercury in the Tube was fuftain’d, he him- 
ielf did not believe it, but run into that Abfurdity of 
the Funicular Hypothecs. 
There is an Inconveniency or Imperfedion in mod, 
if not all, of thofe "Diagonal Barometers } for after 
fome time, the various rifing and falling, and Changes 
of the Weather, of Heat and Cold, the fmall Particles 
of Air that have been interfpers'd in the Mercury , 
have got together in a larger Mafs, as they will incline 
by Attradion, which will feparate the Mercury ; and 
that Quantity of Air will be dilated by Heat , and con- 
traded by Cold , fo as to fpoil the Defign thereof. 
Befides, there is fuch a Cohefion or Attrition of 
the Mercury to the Tube, (efpecially in the fmall ones) 
that after fome time, the Mercury that is not truly 
cleans'd from its Drofs, and purg'd of all its Air , in re- 
markable Changes of the Weather will neither rife 
nor fall. All which Embarrafment is taken off, and 
the Difficulties furmounted, in 
Mr. Cha. Orme’s Improvements of the Ba- 
rometer, hy the Method following. 
Eirft, The Quickfiher is all purified from its Drofs 
and earthy Particles by Diftillation ^ and when the 
Tube is filled by a Pound and half, two, or three Pounds 
of Mercury , and all the Air got out by the Methods 
ufed in filling Tubes , then the remaining Air is got 
out by fuch an intenfe Heat of Fire as makes the 
Mercury boil\ by which Ebullition an innumerable 
Quantity of fmall Particles are emitted, and blo w with 
a great Velocity at the open End of the Tube , till all 
the 
