370

Montgolfier’s

[Book IV.

other. It is a common occurrence, and from the Constitution of the hu-man mind will always be one. A patent was taken out in England forself-acting rams in 1797 by Mr. Boulton, the partner of Watt, and as noreference was made in the specification to Montgolfier, many persons ima-gined them to be of English origin, a circumstance that elicited some re-marks from their author. “ Cette invention (says Montgolfier) n’est pointd’origine Anglaise, eile appartient toute entiere ä la France ; je declareque j'en suis le seul inventeur, et que l’idee ne m’en a ete fournie parpersonne; il est vrai qu’un de mes amis a fait passer, avec mon agrement,a MM. Watt et Boulton, copie de plusieurs dessins que j’avais faits decette machine, avec un memoire detaille sur ses applications. Ce sont cesmeines dessins qui ont ete fidelement copies dans la patente prise par M.Boulton a Londres , en date du 13 Decembre 1797; ce qui est une veritedont il est bien eloigne de disconvenir, ainsi que le respectable M. Watt.”We havb mserted this extract from Hachette, because we really supposedon reading the specification of Boulton’s patent in the Renertory of Arts,(for 1798, vol. ix,) that the various modifications of the ram there des-cribed were the invention of that gentleman. The patent was granted to“ Matthew Boulton , for his invention of improved apparatus and methodsfor raising water and other fluids.”

No. 168. Montgolfier’s Ram. No. 169. The same.

No. 168 represents a simple form of Montgolfier’s ram. The motivecolumn descends from a spring or brook A through the pipe B, near theend of which an air chamber D, and rising main F, are attached to it asshown in the cut. At the extreme end of B, the orifice is opened andclosed by a valve E, instead of the cock in No. 167. This valve opensdownwards and may either be a spherical one as in No. 168, or a commonspindle one as in No. 169. It is the play of this valve that renders themachine self-acting. To accomplish this, the valve is made of, or loadedwith, such a weight as just to open when the water in B is at rest; i. e. itmust be so heavy as to overcome the pressure against its under side whenclosed, as represented at No. 169. Now suppose this valve open as inNo. 168, the water flowing through B soon acquires an additional forcethat carries up the valve against its seat; then, as in shutting the cock ofWhitehurst’s machine, a portion of the water will enter and rise in F, thevalve of the air chamber preventin g its return. When this has taken placethe water in B has been brought to rest, and as in that state its pressureis insufficient to sustain the weight of the valve, E opens; (descends) thewater in B is again put in motion, and again it closes E as before, whenanother portion is driven into the air vessel and pipe F ; and thus the