X. S. H. BARRACLOUGH. 



utilizing through the instrumentality of a second substance 

 the lower temperature ranges, which cannot be effectually 

 worked through with steam as the agent on account of the 

 great specific volume and low pressure of steam at such 

 temperatures. The elaborate experiments by Professor 

 Josse on an engine of comparatively large size, and which 

 in the early part of the year I had an opportunity of inspect- 

 ing at the Oharlottenburg Technical School, have been 

 everywhere watched with great interest. In this engine, 

 as many of you are probably aware, the second working 

 substance was sulphur dioxide, the waste heat from the 

 steam engine proper being used to evaporate the S0 2 which 

 was used as a working substance in a special cylinder. 

 These experiments have now been concluded, but I found 

 that as regards their application to new engines probably 

 not so great a field is available as was at one time thought, 

 as the margin of waste in the primary engine, to be saved 

 in this fashion, is not so great in the modern steam engine 

 as it was in tue earlier ones, and hence there is not so 

 valuable a return to be obtained as an offset to the increased 

 complexity necessarily caused by the addition of a cylinder 

 using a second vapour. It is thought, however, that there 

 are many older reciprocating engines already in use of less 

 than modern maximum efficiency which both in efficiency 

 and output might be improved materially by the addition 

 of the extra parts. A fresh set of experiments is about to 

 be undertaken for the purpose of determining what advan- 

 tage may result from the use of these additional appliances 

 in connection with the waste heat from gas engines, and it 

 is very possible that here a much more promising field 



is available. 

 « 

 For certain classes of work we may assume that the usual 

 type of steam engine will still be largely used, but there can 

 be no doubt that the steam turbine, in one of its now many 



