230 Proceedings of the British Association for [Sept. 



the other institutions of this and of other countries. As an Irishman, 

 and a native of Dublin, I may be suffered in conclusion to add my 

 own to the many voices which welcome this goodly company of Eng- 

 lish, and Scottish, and foreign visitors to Ireland and to Dublin. 

 We cannot, indeed, avoid regretting that many eminent persons 

 whose presence we should much enjoy, arc not in this assembly, 

 though not, we trust, in any case from want of their good will or 

 good opinion. Especially we must regret the absence of Sir David 

 Brewster, who took so active a part in forming this association : but 

 I am authorised, by a letter from himself, to mention that his ab- 

 sence proceeds entirely from private causes, and that they form the 

 only reason why he is not here. Herschel, too, is absent ; he has 

 borne with him to another hemisphere his father's fame and his 

 own; perhaps, from numbering the nebulae invisible to northern 

 eyes, he turns even now away to gaze upon some star which we, too, 

 can behold, and to be in spirit among us. And other names we miss ; 

 but great names, too, are here ; enough to give assurance that in 

 brilliance and useful effect this Dublin Meeting of the Association 

 will not be inferior to former assemblings, but will realise our hopes 

 and wishes, and not only to give a new impulse to science, but also 

 cement the kindly feeling which binds us all together already. 



Tuesday, Wth August,— Dr. Lardner, on Steam Carriages. 

 He commenced, by saying, that at the desire of the British Association, 

 he would address the meeting upon the application of steam gene- 

 rally, but more especially as applied to transport over land. After 

 explaining the properties of steam, and the manner in which water 

 becomes converted into steam, he illustrated the power of this agent 

 by the height with which a plug was raised, when water heated 

 under it became converted into vapour. Thus, every solid inch of 

 water, when converted into steam, is capable of supporting above a 

 ton weight. The speed at which carriages were propelled, depended 

 upon the speed with which steam was applied to the machinery, and 

 subsequently generated in the boiler. Heat operated with greater 

 power than some of his hearers conceived, and, as an evidence, he 

 would mention, that in travelling from Liverpool to Manchester, he 

 found that new grate-bars put into the furnace at Liverpool, were 

 fused and destroyed by the action of the fire. In addition to the 

 present mode of generating steam, there were several other very 

 ingenious plans suggested. By one plan, water was contained in 

 parallel plates, and fire passing up between the water, to use a 

 familiar phrase, became roasted into steam. By another the boiler 

 was formed of consecutive cylinders, placed one within the other, 

 until they terminated in the centre. Another plan had been adopted 

 by Mr. Gurney : great bars formed part of the boiler, and water was 

 contained in them all. Other bars formed the back and also the roof. 

 With reference to the use of engines on railroads, it was well known 

 that no inert body was capable of varying its energies without loss. 

 It was upon this principle, among others, that railways had been 

 found more adapted for transit than stone roads. The latter were 

 variable ; and, from their inequalities, caused a perpetually changing 

 resistance. Iron railroads were superior, from their uniformity. 



