on the Steam Engine. 335 



has yet been contrived for high pressure engines, nor indeed for any- 

 where the tension of the steam exceeds 1^ atrnospheres. Neither are 

 they always applied even to low pressure engines. 



8. The chimney should be provided with a damper, by which the 

 draught of the flues may be suddenly checked, and doors should, if 

 possible, be placed upon the ash pit. A damper that would close as 

 soon as the engine ceased to move, would be of great service; in les- 

 sening the liability to explosion, and this does not appear to be dif- 

 ficult of attainment. 



9. The proof of the boiler should be conducted with the greatest 

 care, first with water, at a pressure five or six times as great as the 

 boiler is intended to carry, and afterwards with steam of twice the pro- 

 posed tension. The water proof should be repeated from time to 

 time, and every part carefully examined to ascertain that all the safe- 

 ty apparatus is in working order. — pp. 101 — 2. 



. The following paragraph presents us with a fearful view, of the neg- 

 ligence which prevails in our country in respect to these precautions. 

 An intelligent gentleman, intimately acquainted with the state of steam 

 boat navigation in this country, has intimated to us, that the negligence 

 is not so great as is here represented. We hope it is not; but the ter- 

 rible disasters that are multiplying upon us, give us too much reason 

 to fear that the account is substantially true. It is as follows. 



Few or none of these precautions are usual in our American steam 

 boats : the boilers, even if cylinders, have both internal flues and fur- 

 naces, and the vertical chimney frequently rises in the boiler ; there 

 is never more than one safefy valve ; plates of fusible metal are un- 

 known; the feeding apparatus is merely a forcing pump, which is turn- 

 ed on or thrown oft' at the pleasure of the engineer, and which does not 

 act at all at the time the engine is not in motion ; but a very few steam 

 boats have dampers upon their flues; and the proof is wholly a matter 

 between the maker and proprietor, and for its proper performance the 

 public have no guarantee. Thus, of all the precautions that have been 

 proposed in order to insure indemnity from explosion, but two are in 

 use among our steam boats, namely, the safety valve and guage cocks; 

 the former being still subject to the caprice of the persons employed, 

 and the latter having an uncertainty in their indications, both when 

 the boat inclines to either side, and when they contain, as they most 

 frequently will do, water of condensation. Need we wonder that ex- 

 plosions have become frequent, and that they have produced the most 

 fatal consequences 1 



The means which are used are not certain to insure safety, even 

 when the care of the officers of the vessel, and of the persons em- 

 ployed about the engine, is unremitting, and directed by the utmost 



