Appleton's Dictionary of Machines, Mechanics, Engine-Work, and Engineering Volume 1 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1856 edition. Excerpt: ...altogether upon the strength its form confers, especially as the form will be changed if the boiler be suffered to become short of water. In round fire-boxes, the sides near the crown (part generally suffer most from waste: these portions are now rovided with stays by Messrs. Bury, urtis, and Kennedy, who are the main sup rtcrs of round ire-boxes; and with this provision the round fire-boxes are necessarily the stronger. e roofs of all fire-boxes require to he stayed by cross-bars; but the bars are required to be both stronger and more numerous for the square fire-boxes, and should always be carefull made of wroughtiron, and very carefully fitted before being bolted on. Stay-bars of custriron have en employed, on account of their cheapncss; but, having led several times to accidents from explosion, they are now discarded. These bars are only in contact with the fire-box at the part around the rivets, and in all the other parts they permit the access of the water below them. It is advisable to bring these bars to an edge on the under side, so as to facilitate the escape of the steam. In Sha and Robert's e wines, the fire-box is made of three plates; the tube-plate and front plate have their e ges bent over, an to these are attached a single plate which forms the crown, and two sides of the furnace. The interior fire-box is joined at foot to the exterior by a Z-shaped iron, which forms the bottom of the water-s cc, and is referred, inasmuch as it leaves a wide water-s ace, and is easily cleaned. The outer an inner fire xes are joined round the furnace door, whic is double, to prevent inconvenient radiation. The external fire-box has sometimes a semi-cylindrical top, joined by turning over the sides like an arch, and sometimes a dome-sha ed...