Sometimes when questions are asked it sets a man thinking deeper than by just reading the text, and a large number of questions has been introduced on subjects mentioned in the book. Direct answers have not been given in all cases, but the reader can refer to index and learn what has been done under similar conditions and study and determine what he would do under like conditions.

A number of books are published purporting to give questions and answers before an examining board when applying for a license.

No man can know the questions that will be asked nor the answers that will be required.

The examiners wish to learn how experienced a man is and the information he has of his own knowledge.

A young man can get much information from the experience of practical men, but this must be supplemented by study, experience and research of his own if he is to impress others with his ability.

It will usually be found that thoroughly well-posted men are willing to give some of their time to imparting information to those whom they think will appreciate and profit by it.

It is generally the rule that it is only those possessing but a small fund of knowledge that become so important with their small lore that are churlish in the

matter.

It is the man that is willing to help others that gets along in life, and it is this man that will become posted in his business.

July, 1906.

W. E. CRANE.

The Boiler Room.

In a boiler room, neatness should be observed in everything. The floor should be kept clean,—and for. this purpose a hose should be conveniently located, the side walls and top of boilers should be cleaned once per week.

All surfaces in contact with the fire should be swept as frequently as time will allow, but the tube surface should be cleaned at least twice per week.

With some classes of boilers, and with fairly clean, soft water washing out once in six months may keep them in good condition, but the water should be changed every two or three weeks. With some types of water tube boilers, where the water enters at the front of the drum, it is frequently only necessary to let the water run out and then turn on the feed water full and the water will wash out all deposit in the drum and mud-drum. With most water tube and with tubular boilers, however, it is necessary to take a hose, and there should be considerable pressure. Where there is scale and considerable mud, the boiler should be gone over thoroughly as frequently as the opportunity offers.

Filtration - Piping-Testing Water.

With very muddy waters a filtration plant will pay, as mud and clay are more to be feared than lime.

With tubular boilers properly set and the water fed at the proper place, the larger part of deposit will be found at the rear end, as that is the part with the slowest circulation.

In water tube boilers the larger part will be found. in the rear circulating tubes, rear manifolds and rear end of tubes.

The important things for a man to look after when taking charge of a set of boilers for the first time is to see that his water gauges are all clear by blowing them all out. Look his piping all over and see if there are any water pockets that would be liable to collect water and let it over in a body; note the position and design of all the stop valves and the manner of getting to them in case of emergency; look the water piping over and the source of supply for the pumps; the type of pumps, and try them to see that they work properly and that there are no broken valves; note the heater, or the absence of any, and test the water to see if it is hard.

This can be fairly well decided by putting some in a pail and washing the hands with soap. If the water is soft there will be nothing but soap suds on top; if hard, there will be a scum formed on top. A chemical analysis will be required to determine the kind of impurity and quantity. Silica means sand and the like, while this mixed with alumina and iron means clay and a dirty boiler.

The safety valves should be looked to. If lever valves, they should be raised to see if they respond readily and if they leak after use.

If "pop" valves, bearing down on the lever will

Safety Valves-Gage Glasses.

cause them to blow, if not set for too high a pressure. At the first opportunity the steam should be raised to the pressure at which it is desired to blow and see that they blow freely from the pressure. Note the blow-off pipe and valves and try the valves. The grates and furnace can be attended to the first time the fire is out. Note condition of brick work, connection of flues, etc., and see if there are any large cracks for air to enter.

When firing up in morning be sure to try the water gauges the first thing, and see that everything about them is free, and that there is no stoppage at top of column, provided the water goes down in the glass and raises partially.

On modern glass gauges there are levers put across the stop cocks and chain attached to both top and bottom so that they can be closed from the floor. These are fastened to the stem with a set-screw. Should this setscrew become loose when the top is closed it will not open and the gauge will show nearly full of water until the water is entirely out of the water column. Any time that the glass gauge shows different from the gauge cocks, either this has hapened or the connections are closed. There was one case on a new boiler where the cocks and glass showed different, the glass showing nearly full, while the cocks showed steam, and it was found that the top glass gauge fitting had no hole through it and no valve seat.

Firing.

When using anthracite coal Professor Thurston's rule is correct-that the fire should be five times as thick as the average piece of coal. This applies to all sizes.

With a fire on a flat grate much thicker than the above there will be a tendency for the coal to melt and

Thickness of Fire-Clinkers.

form an excessive amount of clinker, and if much thinner, too much air will pass through.

Care should be used never to poke or molest a hard coal fire, except when cleaning, and then the fire should not be reduced too thin, even if all the clinkers are not removed, as when disturbed, and too thin, the fire will go out.

It is important that the fire should be kept of uniform thickness, and that this be done with the shovel, and never with hoe or poker.

After cleaning a fire and the first layer of coal is ignited, it is sometimes beneficial to run a thin slice bar along just on top of the grates, and return in the same manner, being careful not to disturb the body of the fire. This loosens up any clinker that may be forming, and keeps the air space open. This slice bar is shown in Fig. I. The cross-piece can be 12 to 15 inches long and 11⁄2 to 2 inches wide. It should not be more than 3% inch thick.

Clinkers that form on the brick are most easily removed after cleaning fires at night, when they are cooling off. They cool on the outside first and contract, which, in a measure, helps to pull them from the wall, and, being in a partially plastic condition at the wall at that time, they are separated with little injury to the wall. The hard case that is formed on the outside of the clinker makes them sufficiently rigid for a poker or breaking-up bar to get a good hold on them. The woman's method is to put oyster shells in the fire next the brick.

Should a slice bar be run under the fire just top of grates every time the fire is replenished, the fire will be kept fairly clean, so that but little cleaning is necessary.