All About Engines

2 All About Engines Cornish, Lancashire, marine, locomotive, or water- tube ? There they are, all of them interesting, and most of them the best for one purpose or another. Let us select one of the vertical type, which is easy to understand and efficient in use. Fig. i shows Fig. 1.—Vertical boiler, Cochran type A, Fire-grate; B, Furnace door; C, Up-take; D, Flue; E, Chimney this boiler in sec- tion, so that the in- terior arrangements can be studied. The fire-grate is wholly surrounded by water, except in one place, where the furnace door is situated. The hot gases pass up into the flue on the right, thence through the tubes until they reach the up-take, lead- ing to the chim- ney on the left. A door in the face of the up-take just above the furnace door enables the tubes to be cleaned out occasionally. Now, if water is heated in an open vessel the temperature, as measured by a thermometer, gradu- ally increases until it reaches 2120 Fahrenheit, or ioo° Centigrade, when the water boils. At this tem-