NEW ENGLAND FARMER. 



i, I, 4, to tlie generator, thus performing 

 )nii>lete circuit. 



lie forcing pump acts with a pressure oxcceil- 

 almosplicres ; coii<eqnently, wlien the 

 pr received in it from the condenser is uryei! 

 tlio generator, it nv.ist expel a portion equal 

 elfin volume : tliis portion, as above de- 

 bed. Hashes instantly into highly elastic 

 The forcing pump, too, is so contriveii 



act with a steady force, and, consequently. 

 expelled water must be driven from the 



erator in a steady current, and thus steam oi 



nstant elasticity is supplied to produce the 



er. 



ome philosophers are of opinion that the 



t of the portion of water which escapes is Oi 



If sutBcient to maintain tlve steam at that 



1 degree of heat and elasticity with which it 

 lies the piston ; and consequently that this 

 ne is nothing more than a High Pressure 

 ine. Other persons, however, have suppo- 



and ne confess we are among that number, 



the portion of water which escapes mu«l 



essarily carry ofl" a quantity of heat fiom the 



lining stratum (the temperature of which 



be thus reduced below the freezing point.) 



it is more likely, that, in virtue of some 



law of the transmission of heat under 



combined conditions of elevated temperature 



high pressure, while the water, also, is 



ed to remain in contact with the red hot 



jrator ; the whole water in the boiler may 



lid under requisition to furnish the discharg- 



fluid with its necessary supply of caloric 



t-] 



is almost unnecessary to stale, that the mo- 

 of the engine is produced by the difTerence 

 ;lasticily between the steam pressing on 

 side of the piston and that pressing on the 

 r. In the first case, the steam recently pro- 

 id, acts with a force, say of 500 pounds, on 

 square inch, while that on the weak side, or 



communicating witli the condenser, acts 



only 70 ; the ditTerence, or 430 pounds, 

 g the true power gained, 

 hen there is a surplus of water in the gen- 

 or, occasioned either by working the fore- 

 amp too violently, or by too veliement a 

 , the water will escape by the tuiie m with 

 live above, loaded with 37 atmospheres, 

 will pass by the pipe 5, 5, 5, into the con- 

 er ST X U. 



order to explain the ingenious manner in 

 ;h the pipe 4, 4, 4, supplies the generator 



vv;iler, we must observe that this pipe 

 municatps with the pump L, which is 

 ight by the engine. 



his pump draws the water by the pipe 6, 6, 

 oni the condenser S T X U, and returns it 

 le pipe 4, 4, 4 ; that is to say, when the 

 le M is drawn up, the water ruslies into 

 ;ylinder of the forcing pump, through a 

 e in the pipe 6, 6, 6, opening into that cyl- 

 r. This valve, of course, instantly closes 

 n the downward stroke of the pump is made, 

 the water uow escapes through a valve ope- 



oulxxards along 4, 4, 4 ; thus etfectually 

 ng off all direct or uninterrupted communi- 

 in between the generator and condenser, 

 ■der to keep the water in the condenser at 

 essure of tive atmospheres, the blast of the 

 iws H goes round the condenser S T X U ; 

 when it is not suflicient for this purjiose, 

 water is introduced from the reservoir L, 



by means of the pipe 7, 7, 7, loaded with five 

 atmospheres. 



l''ioin the high elasticitj' of the steam employ- 

 ed in this engine, it has been suppose<l to be 

 very liable to exjilosion. 'i'his liowever is a 

 vul'^ar error. Since there is no reservoir ot' 

 steam exposing a large surface to its expansive 

 torce, as in the common high pressure ensfines, 

 the steam being generated only in suflicient 

 quantity to pro.luce each succeeding stroke of 

 the piston, the ordinary source of danger is en- 

 tirely removed. iJut, in order to take away all 

 a^qirehensions on that subject, the induction 

 pipe 2, 2, 2, in which the steam is actually gen- 

 erated, is made so strong as to sustain an inter- 

 nal force of 4000 pounds on the square inch, 

 which is eight times more powerful than the 

 actual pressure, viz. 500 pounds on the square 

 inch, with which the engine works. This en- 

 ormous superabundance of strength is still fur- 

 ther secured by means of the safety pipe, 8, 8, 

 8, provided with a tliin copper " safety bulb," a 

 b, which is made so as to burst at a pressure of 

 1000 pounds on the square inch, in order to 

 s.itisly his friends on this very important point, 

 Mr. I^erkins has repeatedly urged the power of 

 the steam to such a degree as to burst the cop- 

 per bulb in their presence. This tube merely 

 rends, or is torn asunder like a piece of paper, 

 and occasions no injury either to the spectators, 

 or to the a[)paratus ; so that we have no hesi- 

 tation in considering this engine, notwithstanding 

 its tremendous energies, as much more safe in 

 its operations than even the common low pres- 

 sure engine. 



The safety tube, 8, 8, 8, communicates also 

 with the indication c d, having a dial-plate c e, 

 and an index e f, which by means of a suitable 

 contrivance at v v, indicates the pressure or 

 number of atmospheres with whicli the engine 

 IS working. 



The cylinder and piston P P Q, have been 

 separated from the rest of the engine, for the 

 sake of distinctness. Their proper position, 

 however, will be understood by supposing the 

 two lines 99 ; 99 to coincide, as well as the 

 tubes 2, 3 ; 2, 3. 



This engine which we have now described, 

 is at present performing actual work in Mr. 

 Perkins's manufactory. It is calculated as 

 equal to a fen horse power, though the cylinder 

 is no more than 2 inches in diameter, and 18 

 inches long, with a stroke of only 12 inches. 

 Although the space occupied by the engine is 

 not more than G feet by 8, yet Jlr. Perkins con- 

 siders that the apparatus, (with the exception 

 of working cylinder P P, and piston P Q_) is 

 perfectly sufficient for a thirty horse engine. 

 When the engine performs full work, it con- 

 sumes only too bushels of coal in one day. 



On tlie application of Mr. Perkins'' principle to 

 Steam Engines of the old construction. 

 Great as the invention is which we have now 

 described, yet we are disposed to think that the 

 application of the principle to old steam engines 

 is not less important. The old engines, with 

 their boilers, are retained unaltered. The fur- 

 naces alone are removed. BIr. Perkins con- 

 structs a generator consisting of three horizon- 

 tal tubes of gun metal, connected together, fill- 

 ed with water, and supplied with water from a 

 forcing pump, as in his own engine. This gen- 

 erator is exposed to beat in an analogous man- 



-1* 



ner, so that by means of a loaded valve, which 

 opens and shuts, the red hot fluid may be con- 

 strained fill forced out of the generato'r info the 

 wafer in the boilers of Rolton & Watt. By this 

 means, as much low pressure steam of four 

 pounds on the square inch may be generated 

 by one bushel of coals, as could be produced in 

 the old engine by nine bushels. This most im- 

 portant result was obtained by actual experi- 

 ment. 



Since these great improvements have been 

 effected, Mr. Perkins has made a discovery that 

 seems, in its practical importance, to surpass 

 them all. He now entirely dispenses with the 

 u«c of the condenser, and works the engine 

 against the atmosphere alone ; and, by methods 

 with which we are not acquainted, and which 

 indeed it would not be prudent for him to dis- 

 close at present, he is enabled to arrest the heat 

 ufler it has performed its mechanical function:-, 

 and actiiaUij pump it back to the generator, to 

 unite with a fresh portion of water, and renew its 

 usful labors. In an operation like this, a con- 

 siderable |)ortiou of the heat must still be lost; 

 but the wonder is that any should be saved ; 

 and we venture to say, that the most sanguine 

 speculator on the omnipotence of the steam en- 

 gine, never dared even to imagine the possibi- 

 lity of such an invention. 



We are well aware, that, in announcing this 

 discovery, we are exposing ourselves to the 

 criticisms of those whose belief is naturally 

 enough limited by their own experience ; but 

 it is satisfactory to know that Capt. Basil Hall, 

 (whose account of Mr. Perkins' discoveries and 

 inventions, as delivered before the Royal Soci- 

 ety of Edinburgh, gave such universal satisfac- 

 tion) has been entrusted with Mr. Perkins' dis- 

 covery, and that he speaks confidently of the 

 soundness of its principles, as well as the prac- 

 ticability of its application. 



We cannot quit this subject without congratu- 

 lating the country on the brilliant prospects with 

 which these inventions promise to invest all our 

 national concerns. At any period of the histo- 

 ry of British industrj', they must have existed 

 in the highest reputation ; but originating as 

 they have done, when our commerce, our man- 

 ufactures, and our agriculture, the three stars a[ 

 our national prosfierity, have just passed the 

 lowest point of their orbit, and quitted, we 

 trust, for long, the scene of their disturbing for- 

 ces, we cannot but hail them with the liveliest 

 enthusiasm, and regard them as contributing to 

 ensure the preeminence of our industry, to aug- 

 ment the wealth and resources of the nation, 

 and, by giving emploj'ment to idle hands, and di- 

 rection to idle minds, to secure the integrity 

 and permanency of our national institutions. 



The London Journal of Arts, for July 1823, 

 has been received. It contains several articles 

 on the subject of Perkins'' Steam Engine. It ap- 

 pears that our countryman had made application 

 for three patents on the subject of his improve- 

 ments and discoveries. The first passed the 

 seal in Dec. 1822, the second was to be specifi- 

 ed in November, and the specification of the 

 third patent to be enrolled in Decemljer, 1823- 

 The Journal adds, 



" An engine (of we believe eighty horse pow- 

 er) upon these improved principles, is in consid- 

 erable forwardness, intended for the purpose of 

 navigation ; and there is great reason to believe 



