"The air pump is an instrument for removing a gas from a closed vessel, the essential parts are shown."…
"Invert the second vessel over the first, mouth to mouth, so that the contents of the two vessels shall…
"If it be required to separate the helium which is often found in the gases given off by a thermal spring,…
"A wood-working tool with a straight or a curved blade and with one or two handles, used to remove address-marks…