6 ROYAL SOCIETY OF CANADA 



years in advance of his time, the projected new steamship " Gigantic," of 

 the White Star hne, being a little longer. 



The increase in the size of vessels has necessitated a coiTcsponding 

 enlargement of docks and wharfs at the great termini of commerce, as, 

 in order to render the trade profitable, it is of the highest importance 

 that the modern ocean palaces should be received, docked and started 

 again with the least possible delay. 



Owing to the keen competition in trade, every effort has been made 

 by rival companies to secure a maximum of economj' in fuel. In the 

 early days the charges for transportation were so high that large profits 

 were obtained with only low pressures of from 20 to 30 lbs., and a corre- 

 sponding consumption of from 5 to 10 lbs. of coal per indicated horse 

 power, but now it is not uncommon to have a working pressure of from 

 180 to 200 lbs., while the consumption of coal is less than 1^ lbs. per 

 indicated horse power. 



Very little progress has recently been made in the theory of the 

 steam engine, and the problem now to be faced is one of great ditficulty; 

 and Avorthy of the attention of the most skilful analj^sts and physicists. 



The laws of the expansion of steam in non-conducting cylinders, as 

 investigated by Clausiusand Eankine, are known not to be even approxi- 

 mately correct when applied to the actual engine. This Avas long con- 

 cealed from view, for the reason that, even under the most diverse 

 conditions as to the supply of heat during expansion, the curves of 

 expansion of the steam, when the pressure and volume are taken as 

 co-ordinates, are hardly distinguishable the one from the other. In 1889, 

 however, Macfarlane Grey read a paper on " The Eationalization of 

 Eeynault's Experiments" before the meeting of Mechanical Engineers at 

 Paris, and showed expansion curves of steam, with the temperature and 

 entropy as the related quantities. From that time increased attention 

 has been directed to the subject, and the extraordinary effect of the walls 

 ujion the form of the expansion curves thus represented has also been 

 made clear. 



Owing to the intricacy of the phenomena of the condensation and 

 re-evaporation of steam during admission, expansion and exhaust, the 

 consumption of steam, as estimated by the ordinary theories, is liable to 

 an error of from 30 to 40 per cent. This can hardly be a matter of sur- 

 prise when the complication of the phenomena is considered. Very little 

 is yet known as to the rate of condensation of steam of ditterent densities 

 and different states of dryness on surfaces very various in character, eg., 

 surfaces black or polished, or covered with an oil film, and again sui-faces 

 on which water is precipitated in drops or as a thin film. Kirsch has 

 applied the Fourier analysis to the general problem of the flow of heat 

 in an engine cj'linder, but the experimental constants necessaiy for even 

 the i^reliminary application of his results are quite lacking. 



