320 Safety Apparatus for Steam Boats. 



open, and when required to be used to prevent the escape of all the 

 steam, will be pressed down, as is usual, by a weight acting by the 

 intervention of a lever. This apparatus should be so placed upon 

 the boiler as to be seen by the passengers, who are thus enabled to 

 know that all is right, while the lever attached to the valve is in an 

 elevated position, showing that the v^alve is raised from its seat; this 

 lever is kept in its raised position, by a cross bar, supported on up- 

 rights, to which it is attached by a strong chain fastened by a pad- 

 lock; the key of this lock being in the possession of the captain of 

 the boat, the chain cannot be slipped, and of course the lever cannot 

 be lowered, to close the valve, except through his agency. Suppose 

 the steam or the boiler to become heated to the fusing point of the 

 plate ; it melts, steam issues through the small cylinder covering the 

 plate, with a noise, which even at night would arouse the captain and . 

 passengers; if no danger will be incurred by loss of steam, and the 

 consequent stoppage of the engine, such an escape should be allowed 

 as a measure of precaution, though it is by no means one of neces- 

 sity, since the limit of temperature producing fusion is much below 

 that required for explosion. The alarm given, the steam gauge, 

 should derangement of the safety valve have prevented its action, or, 

 the usual practical observation upon the issuing steam, will show 

 whether the fusion of the plate was caused by an accumulation of 

 steam, or by the defective supply of water ; this may be further 

 tested by the guage cock ; should it prove that the water is below 

 the usual level, a supply can be introduced without danger. A se- 

 cond plate, arranged in a similar manner to the first, fusible at say 

 20° F. above this, should be also provided, that the same means of 

 safety may remain in case of accident to the first plate. The vigi- 

 lance of the engineer would almost be insured by the use of these 

 plates, from a knowledge that his inattention could not escape de- 

 tection and its consequences. Passengers would be guarded against 

 the results of carelessness, should it exist, and captains, as well as 

 the public, would have the means of knowing accurately the value 

 of those employed in the responsible station of engineers. The 

 want of patronage which would inevitably attend .an ill regulated en- 

 gine, would soon correct evils now so formidable. 



By the annexed figures, the method of arranging the fusible plate 

 and safety valve, is shown in detail. 



