xmxQl^i m P^arine ^oilers. 



By J. W. I. HARVEY. 



Bead befor^e the Engineering Section on March 21sf, 1893. 



THE author having fully explained in detail the data 

 contained in the accompanying table, and that the 

 results had been reduced to a standard evaporation of " from 

 and at 212"^," proceeded to drav/ comparisons between the 

 various systems of draught, and remarked that — 



He had been led to investigate the subject of " Draught " 

 from a desire to ascertain if there are really any grounds 

 upon which the advocates of forced draught are justified in 

 claiming the economy they say attends the application of 

 their various systems. 



And whilst, on the one hand, he had the advantage of 

 the very full and excellent reports of the carefully con- 

 ducted experiments of the " Research Committee on Marine 

 Engine Trials," instituted by the Society of Mechanical 

 Engineers — on the other hand, similar experiments with 

 " Forced Draught " have not been so carefully carried out 

 or recorded ; consequently the requisite data for an ex- 

 haustive comparison of the different systems have not been 

 available. The economical aspect of the subject therefore 

 cannot be fully discussed for want of evidence ; and until 

 similar information as that of the " Research Committee " is 

 forthcoming from some independent source, the advantages 

 or otherwise of " Forced Draught" must remain undeter- 

 mined. 



lis 



