)!H8.| 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



Ill 



inch, A := 27,600 feet of homogeneous atmosphere. The height 

 for other pressures in proportion. 



BEtxISTBB OP KEVT PATENTS. 



SACK HOLDER. 



Henry Gilbert, of St. Leonard's-on-Sea, surgeon, for '''■Im- 

 provements in apparatus for holding sacks to facilitate the filling of 

 them with corn or other materials." — Granted May 27 ; Enrolled 

 November 27, 18+7. 



Heretofore when filling sacks it lias been usual for one person to 

 hold up the sack whil.st the other fills the same. In other cases 

 the sack has been hung from hooks or instruments from a wall or 

 post or some other permanent structure. The object of this in- 

 vention is so to arrange apparatus that it may be carried about 

 with facility, and stand in a field or other place, and uphold a 

 sack in an open state so that the sack may be filled with facility ; 

 the invention simply requiring such an arrangement of parts that 

 it may be independent of a fi.\ed or permanent structure, and be 

 capable of being moved from place to place, and yet uphold an 

 empty sack in an open state and allow of a person readily fill- 

 ing the same. The annexed engraving shows a side and back 

 view of the apparatus, a is the main frame, having two legs a'. 



The sides a are combined together by the bars 6, which are bent to 

 receive the sack as it rests against it ; c is a diagonal frame which 

 turns on axes, and d are two studs or projections fixed to the side 

 rails of the frame, by which the legs or feet can be caused to stand 

 a greater or kss distance apart, there being notches in the pro- 

 jector to receive the studs or projections. At the upper part of 

 the apparatus is fixed an elliptical frame f, througli which the 

 mouth of the sack is to be drawn. The upper part of the sack is 

 to be folded over the bars^, and the clamping-bars brought down, 

 which will clamp the upper parts of the sack securely between the 

 parts//, and g g, by which means the sack will be held open at the 

 mouth and supported or suspended from the frame/ and the appa- 

 ratus may be placed in the position shown in the side view. 



STEAM-ENGINES. 



William Bacon and Thomas Dixon, of Bury, Lancaster, 

 engineers, for '■'■certain Improvements in steam-engines." — Granted 

 August 19, 1847 ; Enrolled February 19, 1848. [Reported in the 

 Patent Journal.^ 



The invention of improvements specified and enrolled under 

 this title applies generally to that class of steam-engines usually 

 termed Woolf 's engine, or the compound-cylinder engine ; that is, 

 an engine having two cylinders, where the steam is admitted into 

 one cylinder, at a high pressure, where having actuated the piston 

 of that cylinder, it is admitted thence to the larger cylinder, 

 where it again produces a motive power, and usually subject to 

 condensation. In one case also, herein specified, it is applicable 

 to single-cylinder engines. The patentee states that in the ordi- 

 nary arrangement of compound-cylinder engines, the area or 

 content of the passages from the expansive valve for tlie high- 

 pressure cylinder to the inside of the low-pressure cylinder are 

 such as to form a large proportion to the cubical content of the 

 high-pressure cylinder ; and that this content or space is filled, at 

 the conclusion of each stroke of the engine, whetlier it be the 

 upward or downward stroke of the low-pressure piston, with steam 

 of a similar density as that produced by its admission into the low- 

 pressure cylinder, which in many cases is five or six pounds, or 

 even more, below the pressure of the surrounding atmosphere^ 

 lirheu the return-stroke of the piston takes place, the steam ad- 

 mitted to effect the preceding stroke of the high-pressure piston 

 is passed into the passage or space before-mentioned, thence to the 

 low-pressure cylinder, where it joins with the before-mentioned 

 rarified steam, and therefore the steam in, or escaping from, the 

 high-pressure cylinder, is considerably reduced in pressure, witli- 

 out producing a corresponding amount of force on the piston. 

 The principal object of these improvements is to obviate in a great 

 measure the before-mentioned deterioration of the steam in its 

 passage from one cylinder to tlie other, and also to simplify the 

 construction and at the same time to obtain an increased amount 

 of duty from the steam in compound-cylinder engines. To attain 

 the advantageous results just enumerated, the patentees construct 

 their improved engine so that by a peculiar arrangement of the 

 passages, valves, and openings, the exhausting-valves for the high- 

 pressure cylinder, or admission-valves for the low-pressure cylinder, 

 are placed as nearly as possible to the ports or entrances to the 

 low-pressure cylinder. On account of this arrangement of the 

 passages between the steam-valves for either of the ports of the 

 low-pressure cylinder, and the opposite end of the high-pressure 

 cylinder, these passages are constantly tilled with steam of the 

 same density as that in the high-pressure cylinder ; therefore, the 

 content of the passage from the valve to the entrance of the low- 

 pressure cylinder is the additional extent of the space the steam 

 admitted to the high-pressure cylinder wiU have to occupy, and the 

 steam always be in reserve for the commencement of the stroke of 

 the low-pressure piston ; consequently the pressure of tlie steam 

 will be reduced but to a very trifling degree ; and, therefore, they 

 argue that a more perfect expansion of the steam in the low- 

 pressure cylinder is obtained, which is attended with a corresponding 

 additional result in the motive-power. These improvements con- 

 sist : — First, in so arranging the valves, passages, and openings, 

 that one valve-box, one double hollow valve (or two sliding-valves 

 of the common construction) are adapted to serve for both the 

 high and the low-pressure cylinders. The same passage in the 

 valve which admits steam to the top of the low-pressure cylinder 

 from the bottom of the high-pressure cylinder, in a downward 

 stroke of the pistons, also forms the passage from the top of the 

 low-pressure cylinder to the condenser, in the upward stroke of 

 the pistons ; and the same passages in the valve which admit the 

 steam to the bottom of the lo^-pressnre cylinder from the top of 

 the high-pressure cylinder, in the upward stroke of the pistons, 

 also forms the passage from the bottom of the low-pressure 

 cylinder to the condenser, in the downward stroke of the pistons. 

 The same part of the valve which admits the steam to the low- 

 pressure cylinder forms the exhausting-valve for the opposite end 

 of the high-pressure cylinder. Secondly, these improvements con- 

 sist in using separate plate or other valves for the admission of 

 the steam to the high-pressure cylinder, and using these valves as 

 expansion-vahes %vith which to cut olt tlie steam from the high- 

 pressure cylinder, and so arranging them that the amount of ex- 

 pansion may be varied to any required extent in the high-pressure 

 cylinder without interfering with the ingress or egress of steam to 

 or from the low-pressure cylinder. Thirdly, these improvements 

 consist in arranging conical-valves, Cornish, or other descriptioQ 



