8 ROUGH-AND-TUMBLE ENGINEER 



Most new pop valves, or safety valves, are set within 

 e pressures. I would advise you to fire to the pop- 

 ping off point, to see that your safety is all right. It is 

 not uncommon for a new pop to stick, and as the Bl 

 runs up it is well to try it, by pulling the relief l< 

 If, on letting it go, it stops the escaping steam at once, 

 it is all right. If, however, the steam continues t 

 cape, 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. \Ve 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, pro- 

 vided your boiler is fitted with the proper appliances, and 

 all builders of any prominence, at this date, fit their boil- 

 ers with from two to four try-cocks, and a glass gauge. 



