1819.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



360 



formeil on the top, upon the lower block being forced from the 

 mouhl; the pressure of steam forces up the loose bottom, and, 

 when up, it is secured by the catch, as before, and the hammer set 

 to work to form another block. The blocks, after beiug com- 

 pressed, are subsequently dried by exposure to tlie atmosphere or 

 heated air. 



STEAM ENGINES. 



AViLLiAM Edward Newton, of 66, Chancery-lane, Middlesex, 

 civil engineer, for "certain improvemmita in steam-enginrx." (A com- 

 munication from Charles M. Keller, Esq., New York.) — Granted 

 December 28, 1848; Enrolled June 28, 1849. [Reported in New- 

 ton's London Journal.~\ 



{With Engravings, Plate XXII.) 



This invention of improvements in steam-engines is represented 

 in the annexed engravings. Fig. 1, is a vertical section of a 

 steam-engine of tlie improved construction, taken in a plane 

 parallel with the beams, and passing through one of the cylinders 

 and the crank-shaft; and fig. 2, is another vertical section, taken 

 at the line a, a, of fig. 1. Figs. 3, and 4, are diagrams of the ordi- 

 nary crank-beam engine, to illustrate the irregular mechanical 

 force on the crank of a steam-engine working expansively. Fig. 5, 

 is a longitudinal vertical section of an improved condensing appa- 

 ratus; fig. 6, is a section thereof, taken at the line b, h, of fig. 5; 

 and fig. 7, is a cross-section of the pumping part of the apparatus, 

 with the auxiliary engine, by which it is operated. 



The inventor, preparatory to explaining the nature of his inven- 

 tion, makes the following introductory remarks: — It is a well- 

 known fact, in the application of steam as a motive power, tliat 

 the nwre the princi])le of expansion is introduced the more econo- 

 mical will be the effect produced, provided some element or ele- 

 ments be not introduced in the mechanism to counteract it. To 

 give tlie full effect to tliis expansive principle of steam, it should 

 be either applied to a resistance which decreases in the exact ratio 

 of the decreasing pressure of the steam, by reason of its expansion 

 or dilatation; or, wliat amounts to the same thing, the leverage of 

 the body, impelled by this force, should increase in the inverse 

 ratio of the decreasing ])ressure. The ordinary crank-engine, in 

 general use, presents in nearly every particular, tlie reverse of 

 the requirements of this problem; and it would be difficult to con- 

 ceive a mechanism theoretically so ill-adapted to the application 

 of this principle; but still, from its practical advantages in other 

 particulars, it continues in use, because of the practical objections 

 to all other plans vvliich have been suggested for overcoming its 

 theoretical defects. The irregular meclianical force of steam ap- 

 plied expansively to the ordinary crank-beam engine, is illustrated 

 in diagrams 3, and 4, — the former being based on the assumption 

 that the steam is cut off at one-quarter of the stroke, and the lat- 

 ter at one-twentieth. In these diagrams, a, represents the cylin- 

 der; i, the piston; c, tlie piston connecting-rod; d, the beam; e, 

 the crank connecting-rod; /, the crank; g, the circle described by 

 the centre of the crank-pin in tlie rotation of the crank; and i, 

 the line of pressure of the expanding steam. When the steam is 

 cut off at one-quarter of tlie stroke, one-half of the wliole me- 

 chanical force of the steam is expended in forcing the piston up to 

 the dotted line h, a little more than one-quarter of the entire 

 stroke, — tlie crank making but about one-third of its semi-rotation 

 from tlie dead point, and therefore along that part of the rotation 

 in which it presents the shortest leverage. During the next quar- 

 ter of the stroke, the crank passes to the line j, which indicates 

 the half of the semi-revolution; and, in passing to this point, tlie 

 leverage of the crank increases nearly in the inverse ratio of the 

 decreasing pressure of the steam on the piston; but this is the 

 only part of the stroke in which the motion and leverage of the 

 crank are in such relation to each other as togive an approxiniaton 

 to the full mechanical force of the steam; whereas, during the re- 

 maining half-stroke, the leverage of t!ie crank decreases as the pres- 

 sure decreases. The great defect is to be found in the fact that 

 (when the steam is cut off at the quarter-stroke) one-half of the 

 mechanical force of the steam is exerted in moving the crank 

 through only one-third of the circuit due to the entire stroke, — -the 

 other two-thirds remaining to be effected by the otlier half of the 

 mechanical force of the steam, and that too by a force decreasing 

 as the leverage to which it is applied decreases. But it will be seen, 

 by reference to the diagram, fig. 4, that this irregularity, so wasteful 

 of power, increases as the steam is cut off at a less portion of the 

 stroke, — as, for instance, in this diagram the steam is supposed to 

 be cut off at one-twentieth of the sti'oke. In this, the line of mean 



pressure h, is at one-eighth of the stroke; and therefore one-half of 

 the mechanical force of the steam has been exerted in moving the 

 piston only one-eighth of its stroke, — the remaining seven-eighths 

 of the stroke ha\ing to be effected by the remaining half of the me- 

 chanical force. It follows, from these illustrations, that the more 

 expansively steam is applied to the ordinary crank-engine, the 

 more irregular will be tlie motion, and the more wasteful the 

 application of the impelling force. 



In view of the problem above given, and the theoretical defects 

 of the ordinary engine, the desideratum has been the production 

 of an engine which would present all the practical advantages of 

 the ordinary crank-engine, such as simplicity and cheapness of 

 construction, strength and durability, and which, at the same time, 

 would admit of a more economical application of the principle of 

 the expansion of the steam. 



The accomplishment of this important end is the object of the 

 first part of tlie present invention, which consists, first, in placing 

 the axis of the crank-shaft in a plane nearer than heretofore to 

 the axis of vibration of the beam which transfers the power from 

 the piston to the crank; that is, instead of placing the axis of the 

 crank-shaft in a plane midway between a plane passing through 

 the axis of the connection of the connecting-rod with the beam at 

 the two extremities of its vibrations, and a plane parallel to it, 

 and passing through this point of the beam at the middle of the 

 vibration, it is placed within this plane, — that is, in or near a 

 straight line, passing through the axis of the connection of the 

 connecting-rod and beam at the extremities of the vibrations of 

 the beam; whereby less than the first half of the stroke of the 

 piston shall carry the crank through one-half of its semi-revolu- 

 tion, — that is, from the dead point to the right angle; and the 

 remaining portion of the stroke, more than one-half, shall give to 

 the crank the remaining half of the semi-revolution, — that is, 

 carry it from the right angle to the other dead point, and, at the 

 same time, bring the line of the connecting-rod (which is shorter 

 than heretofore, say a little more than double the throw of the 

 crank), nearer to a right angle with the crank during the second 

 half of its semi-revolution than during the first-half; and thus 

 not only increase the proportional velocity of the piston whilst 

 impelled by the expanding steam, but make it act on a longer lever 

 than by any other known crank-engine. Secondly, in combining 

 with the crank-shaft, located on the principle herein specified, two 

 single-acting engines, acting on cranks placed on the shaft at an 

 angle of 180°; whereby the force of expanding steam maybe more 

 economically applied, and a more regular motion obtained, than 

 heretofore And, thirdly, in making the second engine of greater ca- 

 pacity than the first, anii receiving steam at one end only, and from 

 the first; this end being also alternately connected with the first en- 

 gine, to receive steam, and with the condenser for exhausting, that 

 the piston may be acted upon in one direction by the expansion of 

 steam, after it has acted in the first engine, there being a vacuum 

 on both sides of the piston during its return motion, when this is 

 combined with the first engine, which receives the steam at one 

 end only, — its other end being connected with that end of the 

 second engine which receives the steam ; so that, during the return- 

 stroke of the piston in the first engine, it shall be balanced by the 

 expanding steam, whilst it is acting on the piston of the second 

 engine. 



In the drawings at figs. 1, and 2, a, and b, represent two beams, 

 having the same axes of vibration, and both of the same propor- 

 tions. The short arm of the one a, is connected by a rod c, with 

 the piston-rod d, of a piston e, that works in the cylinder/, of the 

 first engine; and the corresponding arm of the other beam 6, is in 

 like manner connected with a piston g, working in the cylinder h, 

 of the second engine (see fig. 2), and which is to be placed as near 

 as practicable to the first. The long arms of the two beams are 

 connected by rods ij, with two cranks /c, /, on the crank-shaft m, 

 and opposite to each other; that is, dividing the circle into two 

 equal parts, that one piston may be up whilst the other is down, 

 and vice versa. The connecting-rods iJ, should be about two and 

 a half times the length of their cranks. The axis of the crank- 

 shaft is in the straight line n, passing through the centres of the 

 connection of the connecting-rods i,j, with the beams a, i, when at 

 the extremity of vibration of the beams; from which position, 

 relatively to the proportions of either one of the beams and length 

 of crank and connecting-rod, it results, that the long arm of the 

 beam, in being moved to the position indicated by the dotted line 

 ;), about one-third of its entire vibration, by one-third of the down- 

 stroke of the piston e, will carry the crank /r, from the dead point to 

 the right angle, one-half of its' semi-revolution, as indicated by the 

 dotted lines /i; and that in passing through the remaining two-thirds 

 of its vibration, to the position occupied in the drawings by the beam 



48 



