Thermometer, description of, [24]
Throttle valve, use of, [104]
Traction, force of, on a railroad, [192]
Tredgold, [70]
Trevithick and Vivian, Messrs., construct the first high-pressure engine used in this country, [148]
U.
United States, steam communication with, [274]
V.
Vacuum, production of, by experiment, [37]
Vapour, elastic, force of, [35]