Chap. 8.] Savery claims a share in Newcomen ’s Patent. 4G7

most instantaneously, and produced a vaouura with far less water thariwhen applied to the exterior of the cylinder. This led Newcomen toremove the outer cylinder, and to insert the lower end of the pipe f intothe bottom of a, so that on opening the cock f a jet of cold water wasprojected through the vapor. This beautiful device is the origin of theinjection pipe still used in low-pressure engines.

Newcomen and Cawley’s engine, as figured page 465, was improved inseveral parts in 1712, and soon after adopted as a hydraulic machine fordraining the coal and iron mines in various parts of Europe . Veryelaborate engravings of some used in French mines may be seen in thefolio edition of Arts et Metiers. See also Desaguliers ’ Ex. Philos. vol. ii,and Switzer’s Hydrostatics.

The application of sectors and chains to pump rods did not originate withNewcomen . They are figured by Moxon, and were probably employedin working pumps in mines previous to the invention of the steam-engine.

We have often thought the heaviest charge against Savery was to befound in his conduct towards Newcomen and Cawley. Their machinewas essentially different from his in its principle, construction and modeof action, yet he insisted that it was an infringement upon his patent. Heemployed the pressure of the atmosphere in charging his receivers, bycondensing with cold water the steam within them. So far as regardsthis mode of forming a vacuum, (he in his receivers and they beneath apiston) there is a resemblance between the two machines, but no farther;and this plan of making a vacuum was not original with him any morethan with them. It was no more a new device in his time than his paddlewheels were. The object of Newcomen and Cawley in forming a vacuumwas also quite different from his; for they did not raise water into thevacuity, but employed it solely to excite the pressure of the atmosphereupon the upper side of a piston, in Order to impart motion to commonpump rods. Again, he used the expansive force of high steam : this wasthe prominent feature in his machine, and the great power that gave effi-ciency to it; but they did not use this power at all. The weight of theexternal air, not the expansive force of steam, was the primum mobile intheir machine, and it was brought into action by the vapor of water at theordinary boiling point.

But as they formed a vacuum in their cylirjder by the eondensation ofsteam, he insisted on having a share in their patent! The fact was hismachines had become in a great measure laid aside, and he doubtless per-ceived that they were destined to be wholly superseded. Desaguliers (in 1744) observes that the progress and improvement of the fire enginewere stopped by the difficulties and dangers attending it, tili Newcomen and Cawley “ brought it to the present form, in which it is now used, andhas been near these thirty years.” Unless his name was included as ajoint patentee, Savery threatened an appeal to the law; and it is said hisinfluence at court, as commissioner for the sick and wounded, gave weightto this ungenerous and unjust demand. Newcomen we are informed wasa Quaker, or like Cawley a Baptist, and therefore on principle averse tolegal controversy : he was moreover a man of “ a great deal of modesty,”and so yielded the point. The patent was consequently issued (in 1705)“ to Thomas Newcomen and John Cawley of Dartmouth , and Thomas Savery of London .”

Another point has been generally overlooked : so far from Newcomen ’smachine being an infringement or improvement upon Savery ’s, it was reallymvented as early if not earlier than the latter. Switzer (Savery ’s friend)says, “ it [Newcomen ’s engine] is indeed generally said to be an improve-