The above expense includes pay of members, team expenses, cost of gas, wood, coal, and all necessities incident to service. The "E.W. Harrington" is a second-class engine, stationed in the outskirts of the city, and was run cheaper from the fact that no horses were kept for it by the city.
A first-class hand-engine company is allowed to number, all told, fifty men, and the members of the company are paid as follows:
| FIRST-CLASS HAND-ENGINE COMPANY. | ||
| 1 foreman | $35 00 | |
| 1 assistant foreman | 28 00 | |
| 1 clerk | 28 00 | |
| 1 steward | 68 00 | |
| 46 men, at $18 each | 828 00 | |
| -- | -------- | |
| 50 men. | Total | $987 00 |
By this it will be seen, that in a city like Manchester, with from twenty to twenty-five thousand inhabitants, a first-class steam fire engine can be run at an expense not to exceed that of a first-class hand engine, while in service it will do at least four times the work. The cost of repairs is found by experience to be no greater on the steam fire engines than on hand engines.
The Excavator, fig. 76, is the invention of the late Mr. Otis, an application of the spoon dredging machine of the docks to railway purposes, with very important modifications. The machine consists of a strong truck, A, A, mounted on railway wheels, on which is placed the boiler C, the crane E, and the requisite gearing. The excavator or shovel, D, is a box of wrought iron, with strong points in front to act as picks in loosening the earth, and its bottom hung by a hinge at d, so that, by detaching a catch, it may fly open and discharge the material raised. To operate the machine, suppose the shovel D to be in the position shown in the cut; it is lowered by the chains o, o, and thrown forward or backward, if necessary, by the drum B, and handle S, till the picks in the front of the shovel are brought in proper contact with the face of the cut; motion forward is now given to the shovel by the drum B and handle S, and at the same time it is raised by the chains o, o. These two motions can be so adjusted to each other, as to give movement to the shovel to enable it to loosen and scrape up a shovelful of earth. The handle S is now left free, and the shovel D is raised vertically by the chains o, o. The crane is now turned round, till the shovel comes over a rail car on a side track; the bottom of the shovel is opened, and the dirt deposited in the car. All these motions are performed by the aid of a steam engine, and are controlled by a man who stands on a platform at f.
692. Q.--Having now described the most usual and approved forms of engines applicable to numerous miscellaneous purposes for which a moderate amount of steam power is required, will you briefly recapitulate what amount of work of different kinds an engine of a given power will perform, so that any one desiring to employ an engine to perform a given amount of work, will be able to tell what the power of such engine should be?
A.--It will of course be impossible to recapitulate all the purposes to which engines are applicable, or to specify for every case the amount of power necessary for the accomplishment of a given amount of work; but some examples may be given which will be applicable to the bulk of the cases occurring in practice.
693. Q.--Beginning, then, with the power necessary for threshing,--a 4 horse power engine, with cylinder 6 inches diameter, pressure of steam 45 lbs., per square inch, and making 140 revolutions per minute, will thresh out 40 quarters of wheat in 10 hours with a consumption of 3 cwt. of coals.
A.--Although this may be done, it is probably too much to say that it can be done on an average, and about three fourths of a quarter of wheat per horse power would probably be a nearer average. The amount of power consumed varies with the yield.