ROl TUMBLE ENGINEEK 13 



You, as a matter of course, want to know why this can 



do any harm, it couKi not, if the water in the boiler 



ws in the glass, but it is not always 



i.l that is what causes the trouble. You 



probably have lived long enough in the world to know 



that there are a great many boys in it, and it seems to be 



second nature with them to turn everything on an engine 



>ssible to turn. All glass gauge cocks are fitted 



with a small hand wheel. The small boy sees this about 



the first thing and he begins to turn it, and he generally 



I as long as it turns easy, and when it stops he will 



other one. and when it stops he has done the 



hief, by shutting the water off from the boiler, and 



all the water that was in the glass remains there. You 



c stopped work with an ordinary gauge of water, 

 and as water expands when heated, it also contracts when 

 it becomes cool. Water will also simmer away, if there 

 is any fire left in the fire box, especially if there should 

 be any vent or leak in the boiler, and the water may by 

 morning have dropped to as mi: i inch below the 



ieet. You approach the engine and on looking 

 at the glass sec two or three inches of water. Should 



a fire without investigating any further, you 



will have done the damage, while if you try the gauge 



cocks first you will discover that some one has tampered 



engine. The boy did the mischief through no 



