12 THE HISTORY OF [SECT. i. 



inclined to set a higher value upon it than on the fortuitous discovery of a new 

 principle. To point out what is actually due to Newcomen would be difficult, and 

 for want of evidence we must be content with examining the state of the engine. 

 The admission of steam below an air-tight piston, attached to the impelled point of 

 a lever properly counterpoised ; its rapid condensation by injection of water, which 

 is essential to gain effect ; and the mode of clearing the cylinder of air and water 

 after the stroke, are all additional to the principles and mechanism before in use ; 

 and these are wholly due to Newcomen, or those connected with him. 



1718. HENRV BRIGHTON, F.R.S. ; died 1743. 



11. The arrangement of the parts of the atmospheric engine, the mode of 

 fixing, and the mechanism for opening and shutting the valves, were greatly 

 improved by Mr. Henry Beighton, an engineer, of Newcastle-upon-Tyne. He also 

 seems to have been the first to reduce the calculation of the powers of engines to a 

 regular system, and published a ' Table of the Dimensions and Power of the 

 Steam Engine,' in 1717, which has been found to accord with practice ; 2 and he 

 directed the construction of several large engines. He also remarked the fact of 

 steam heating a very large proportion of water in condensing, and communicated 

 to Dr. Desaguliers some experiments on the bulk of steam formed by a given 

 quantity of water, the result of which was erroneously stated, in consequence of a 

 singular mistake in the calculation ; and it is also obvious, that the mere quantity 

 of water, and bulk of the cylinder, could not possibly give the result he expected, 

 even on the supposition that the cylinder was maintained at 212 during the 

 experiment. 3 I cannot leave the memory of Beighton without the remark, that 



1 Dr. Hutton remarks, it is probable that Mr. Beighton died in 1743 or 1744, as it appears that 

 he conducted the Ladies' Diary for the Stationers' Company, from 1714 to 1744 inclusively ; 

 discharging that trust with such satisfaction to the Company, that they permitted his widow to 

 enjoy it for many years afterward, by employing a deputy to compile that very useful annual little 

 book. In that almanack, for the year 1721, Mr. Beighton inserted a curious table of calculations 

 on the steam engine. Phil. Trans. Abrid. vii. p. 442. 



2 Desaguliers' Course of Experimental Philosophy, ii. 534. 



3 In Mr. Beighton's experiment (Desaguliers' Ex. Phil. ii. 533.) made on the steam engine, to 

 know what quantity of steam a given quantity of water produces, he found by several trials with a 

 divided steelyard on the safety valve on the top of the boilers at Griff and Wasington, that when 

 the elasticity of the steam was just one pound on a square inch, it was sufficient to work the 

 engine ; and that about 5 pints in a minute would feed the boiler, as fast as it was consumed in 

 producing steam for the cylinder at 16 strokes per minute. Griffs cylinder held 113 gallons 

 of steam every stroke; hence 113x16=1808 gallons=14464 pints; therefore 5 pints of water 

 produced 14464 pints of steam ; consequently, 1 pint would produce 2893 pints of steam of that 



