"This coffee apparatus consists of a glass globe a, an infusing jar b, of glass or porcelain and a bent tube c of block tin or German silver fitted by a cork stopper into the neck of the globe and passing to the bottom of the jar, where it ends in a finely perforated disc. The apparatus also requires a spirit lamp d or other means of communicating a certain amount of heat to the globe. The coffee is infused with boiling water in the jar, and a small quantity of boiling water is also placed in the globe. The tube is then fitted in, and the spirit lamp is lighted under the globe. The steam generated expels the air from the globe, and it bubbles up through the jar. When the bubbles of air cease to appear almost the whole of the air will have been ejected, and on withdrawing the lamp the steam in the globe condenses, creating a vacuum, to fill up which the infused coffee rushes up through the metal tube, being at the same time filtered by the accumulated coffee grounds around the perforated disc." — Encyclopedia Britanica, 1893

Napier's Coffee Apparatus

"This coffee apparatus consists of a glass globe a, an infusing jar b, of glass or porcelain and a bent…

Illustration of a right spherical triangle and the five circular parts placed in the sectors of a circle in the order in which they occur in the triangle. "The ten formulas used in the solution of spherical right triangles can be expressed by means of two rules, known as Napier's rules of circular parts."

Napier's Right Spherical Triangle

Illustration of a right spherical triangle and the five circular parts placed in the sectors of a circle…