Rough and Tumble Engineering | Page 3

as the steam runs up it is well to try it, by pulling the relief lever. If, on letting it go, it stops the escaping, steam at once, it is all right. If, however, the steam continues to escape, the valve sticks in the chamber. Usually a slight tap with a wrench or a hammer will stop it at once, but never get excited over escaping steam, and perhaps here is as good a place as any to say to you, don't get excited over anything. As long as you have plenty of water, and know you have, there is no danger.
The young engineer will most likely wonder why we have not said something about the danger of explosions. We did not start to write about explosions. That is just what we don't want to have anything to do with. But, you say, is there no danger of a boiler exploding? Yes. But if you wish to explode your boiler you must treat it very differently from the way we advise. We have just stated, that as long as you have plenty of water, and know you have, there is no danger. Well, how are you to know? This is not a difficult thing to know, provided your boiler is fitted with the proper appliances, and all builders of any prominence, at this date, fit their boilers with from two to four try-cocks, and a glass gauge. The boiler is tapped in from two to four places for the try-cocks, the location of the cocks ranging from a line on a level with the crown sheet, or top of fire box, to eight inches above, depending somewhat on the amount of water space above the crown sheet, as this space differs very materially in different makes of the same sized boiler. The boiler is also tapped on or near the level of crown sheet, to receive the lower water glass cock and directly above this, for the top cock. The space between this shows the safe variation of the water. Don't let the water get above the top of the glass, for if you are running your engine at hard work, you may knock out a cylinder head, and don't let it get below the lower gauge, or you may get your head knocked off.
Now the glass gauge is put on for your convenience, as you can determine the location of the water as correctly by this as if you are looking directly into the boiler, provided, the glass gauge is in perfect order. But as there are a number of ways in which it may become disarranged or unreliable, we want to impress on your mind that you, must not depend on it entirely. We will give these causes further on. You are not only provided with the glass gauge, but with the try-cocks. These cocks are located so that the upper and lower cock is on or near the level with the lower and upper end of the glass gauge. With another try-cock about on a level with the center of glass gauge, or in other words, if the water stands about the center of glass it will at the same time show at the cock when tried. Now we will suppose that your glass gauge is in perfect condition and the water shows two inches in the glass. You now try the lower cock, and find plenty of water; you will then try the next upper cock and get steam. Now as the lower cock is located below the water line, shown by the glass, and the second cock above this line, you not only see the water line by the glass, but you have a way of proving it. Should the water be within two inches of the top of glass you again have the line between two cocks and can also prove it. Now you can know for a certainty, where the water stands in the boiler, and we repeat when you know this, there is nothing to fear from this source, and as a properly constructed boiler never explodes, except from low water or high pressure, and as we have already cautioned you about your safety valve, you have nothing to fear, provided you have made up your mind to follow these instructions, and unless you can do this, let your job to one who can. Well, you say you will do as we have directed, we will then go back to the gauges. Don't depend on your glass gauge alone, for several reasons. One is, if you depend on the glass entirely, the try-cocks become limed up and are useless, solely because they are not used.
Some time ago the writer was standing near a traction engine, when the engineer, (I guess I must