EXPLANATION OF THE PLATES. 371 



"My invention does not consist in the novelty of any one of the five apparatus 

 hereinafter mentioned, but in the combination of the whole five, or at least three out of 

 the five, within proper proportions, (as hereinafter described,) as regards the first three, 

 which I have found by experience to be beneficial, and from the want of knowing 

 and observing which I have reason to believe that all persons who have made 

 former attempts of the same nature have failed. I now proceed to describe the 

 above mentioned five apparatus, consisting of 



" First, a sufficient quantity of metallic surfaces in the form of vessels, channels, 

 passages, or pipes of any convenient form, arrangement, or construction. The extent of 

 such metallic surfaces should be about 2800 square inches for the condensation of 60,000 

 cubic inches of steam per minute. 



" Secondly, a pump or any other proper apparatus for the passing of a sufficient 

 quantity of cold water amongst such above mentioned pipes, not only to condense all 

 the steam of steam engines, but also to cool the water resulting from the condensation 

 thereof, to as low a temperature as (or even lower than) that of the mixture of the 

 condensed steam and injection water, which is discharged from the air pumps of 

 injection engines, in order to produce by such application of cold water, when used 

 in combination with the metallic surfaces, as above stated, and with the air-pump 

 hereinafter mentioned, as good a vacuum as is obtained and well known in such 

 injection engines, if not indeed a still more perfect vacuum. The quantity of cold 

 water which I employ is ten gallons for such condensation of such 60,000 cubic inches 

 per minute. 



" Thirdly, the ordinary air-pump of the capacity hereafter stated to produce, when 

 in conjunction with the before mentioned two apparatus, a sufficiently perfect vacuum, 

 as above defined. 



" Fourthly, an apparatus for distilling water to replace the waste of water that may 

 take place in the working of the engine, in order to avoid, as above mentioned, the 

 introduction of any water into the boilers containing saline or other extraneous 

 matters. 



" Fifthly, an apparatus, which I call the steam saver, for saving the steam that 

 usually escapes into the atmosphere from the safety valves, when it becomes of too 

 high pressure during the working of the engine, the apparatus causing such steam to 

 pass into the condensers to be converted into water and return to the boiler. 

 It may be proper here to remark, that within certain limits which experience will 

 readily suggest, the above mentioned proportions of metallic surfaces of cold water 

 and capacity of the air-pump may be varied in a certain inverse order, that is to say, 

 if the cold water be diminished, the extent of metallic surfaces or the capacity of the 

 air-pump, or both, should be increased ; and on the other hand, if the extent of 



