18 TEAR-BOOK OF FACTS. 



appeared to be that the practical introduction of the system of super- 

 heating steam was greatly owing to the exertions of Mr. Wethered. 

 He had succeeded iu moving the British Board of Admiralty, when, 

 perhaps, an English engineer might not have been so successful ; but 

 this should be a subject of congratulation, as it was desirable at all 

 times to give the greatest encouragement to foreigners, so as always 

 to attract the best talent from other countries. The case did not, 

 however, seem to be clearly established in favour of combined steam. 

 It rested upon the facts which had been stated, and not upon any 

 scientific explanation of the rationale of the principle, such as would 

 account for the results claimed for it. "When more than ordinary 

 attention was given to any machine in daily use, that of itself would 

 often lead to economy. This attention was invariably given when 

 any new invention was being tried, and the whole improvement or 

 economy was supposed to arise from the particular modification then 

 being tested. 



IMPROVEMENTS IN APPARATUS FOR REFRIGERATING AND 

 CONDENSING. 

 Mr. J. P. Joule, F.R.S., of Manchester, has paten ted an invention 

 which consists in a method of applying a stream of water or other 

 liquid to the surface of tubes or other receptacles of liquids or elastic 

 fluids, so as to occasion an increased and more rapid interchange and 

 equalization of temperatures. This he effects by placing spirals or 

 spiral coils in the pipes or channels, by means of which spiral coils 

 the stream of water or other liquid is made to acquire a progressive 

 and spirally rotatory motion ; or the same effect may be obtained by 

 placing plates or vanes, so as to divert the stream from its original 

 course into a spiral direction. In the instance of the "Surface 

 Condenser' of a steam-engine of that description, in which the 

 exhaust steam is passed through tubes placed within tubes of a 

 larger diameter, the concentric space between the tubes being used 

 for the transmission of a stream of cold water, he places a spiral coil 

 upon the outside of the inner tube, by means of which the water is 

 compelled to follow the direction of the convolutions of the spirally- 

 formed coil instead of going straight along the space between the 

 tubes. If the surface condenser, on the other hand, be of the 

 kind in which the exhaust steam is made to enter a receiver through 

 which the refrigerating water is transmitted by means of metallic 

 tubes, he places spiral coils within the tubes, and thus causes the 

 r to follow the direction of the coils. In the instance of a re- 

 frigerator or other apparatus for cooling hot liquids by a stream of 

 water carried through pipes, he plaoes in each pipe a metallic or 

 other spirally-formed coil ; or when one pipe is placed within another 

 of larger dimensions, the spaoa between the two conveying the liquids 

 to be oooled or heated, and tli«' inner tube oonveying the liquid in the 

 process of heating or cooling, be plaoes spiral coils in the space 



between the tubes, and also witilin the inner tube: the spiral coils 



may be constructed of OOppN or other suitable material, and if of 

 small sise, may be made by bending or coiling wire around a 



