"The pressure of the atmosphere may be easily shown by the tube and piston. suppose there is an orifice to be opened or closed by the valve b, as the piston a is moved up or down in its barrel. The valve being fastened by a hinge on the upper side, on pushing the piston down, it will open by the pressure of the air against it, and the air will make its escape. But when the piston is at the bottom of the barrel, on attempting to raise it again, towards the top, the valve is closed by the force of the external air acting upon it. If, therefore, the piston be drawn up in this state, it must be against the pressure of the atmosphere, the whole weight of which, to an extent equal to the diameter of the piston, must be lifted, while there will remain a vacuum or void space below it in the tube. if the piston be only three inches in diameter, it will require the full strength of a man to draw it to the top of the barrel, and when raised, if suddenly let go, it will be forced back again by the weight of the air, and will stright the bottom with great violence." —Comstock, 1850

Atmospheric Pressure

"The pressure of the atmosphere may be easily shown by the tube and piston. suppose there is an orifice…

"As the liquid flows out of each orifice, each stream follows a parabolic path based upon pressure of the liquid inside the container. Orifices A and C are equidistant, thus reach the same point." —Quackenbos 1859

Course of Streams

"As the liquid flows out of each orifice, each stream follows a parabolic path based upon pressure of…

A syringe is a simple piston pump consisting of a plunger that fits tightly in a tube. The plunger can be pulled and pushed along inside a cylindrical tube (the barrel), allowing the syringe to take in and expel a liquid or gas through an orifice at the open end of the tube.

Syringe

A syringe is a simple piston pump consisting of a plunger that fits tightly in a tube. The plunger can…

A window with a hinged sash that swings in or out like a door comprising either a side-hung, top-hung, or occasionally bottom-hung sash or a combination of these types, sometimes with fixed panels on one or more sides of the sash.

Casement Window

A window with a hinged sash that swings in or out like a door comprising either a side-hung, top-hung,…