Three chemicals are used, ammonia, hydrogen gas, and water. At room temperature ammonia is normally a gas that has a boiling point of -33°C, however, the absorption cooling system is pressurized to the point that the ammonia is held in a liquid state at room temperature.
The engraving shows a light and compact velocipede carriage of German invention, calculated for easy and comfortable riding and capable of carrying light baggage. The rider 'sits in an easy chair above the forward axle, and grasps the guiding handles attached to this axle. The feet rest upon pedals connected by rods with cranks on the rear axle. By the alternate movement of the pedals the carriage is propelled. A lantern is carried in front, and a canopy covers the head of the rider.
Front page wood engraving of the June 18, 1881 Scientific American weekly journal.
Title: Professor A. E. Dolbear's New Telephonic System
In 1885 a German scientist Robert Bunsen invented a device to mix air with natural gas in the correct proportions. The Bunsen Burner machine opened up many new opportunities for the use of natural gas in everyday use. Adding thermostatic devices to regulate the flame and so control temperature made it popular for heating and cooking. This invention helped change the use of natural gas from a wasted nuisance around oil and coal to a popular energy source.
From the February 27, 1858 Illustrated London News
Woodcut image made from a photo
Used in an assassination attempt on FRENCH EMPEROR Louis Napoleon