120 



THE CIVIL ENGINEERIAND ARCHITECrS JOURNAL. 



[April, 



aad smoke after Ic-aving the furnace, shall pass into a chamber below the 

 furnace and at the back of the ash pit, which is constantly supplied with air, 

 and be there deflected by a " hanging-bvidge'' so as to mix intimately with 

 the atmosphere and be inflamed by it. 



CAULKING SHIPS. 



Sasah Coote, of Clifton, for "improvements in caulking ships ntiil otiier 

 vessels."— Granted July 21, 1844 ; Enrolled January 24, 1845. 



Under this invention the use of flax and hemp is discarded and shorn wool 

 substituted. This substance is first picked and then saturated with paint of 

 white lead. After the paint is strained oil, the wool is ready for use. 



FARRELL'.S ARCHIMEDEAN* (.SPIRAL) RAILWAY. ' 



This is a scheme for propelling railnay carriages by stationary steam en- 

 gines. Mr. Farrell is an architect of Dublin, and his patent bears date Nov. 

 14, 1844. The principle of the invention is similar to the well known con- 

 trivance of turning a cog-wheel by placing its cogs in gearing "itb llie thread 

 of the revolving screw. An endless screw is laid down between the rails, the 

 whole length of the railway. This endless screw is turned by stationary en- 

 gines, and two wheels fixed to the foremost carriage of the train are acted 

 upon by the thread of the screw, which thus gives motion to the train. 



Fig. 1, Pkite 9. is an elevation of a carriage and a portion of the railway. 

 The screw propeller is keyed to the shaft a by w rought-iron arms e, to the 

 end of which the spiral is bolted at c. The shaft is divided into lengths of 

 about 12 feet each, and the two ends of each lengih turn on bearings attached 

 to the cross-sleepers. The lengths are connected at the bearings so as to 

 turn together. Fig. 2 is a cross section, a the shaft, and b the connecting 

 arm as in fig. 1. c the circle which any point of the spiral describes in its 

 rotation ; a a the wheels which bear on tlie thread of the spiral and com- 

 municate motion to the carriage ; h, m, i, refer to mechanism for disconnect- 

 ing the pair of wheels from the spiral when the train is to be stopped. 



The following passa-es from Mr. Farrell's published account of his system 

 seem the most material. 



*' The shafting is proposed to be formed Jof iron'' tubing 4 inches diameter, 

 and half an inch in thickness ; the weight found by accurate calculation and 

 proved by e.\-periment as sufficient to twist such a shaft if applied to the peri- 

 phery of an 18-inch pinion fast on it is 22,1961b. ; now, as half the breaking 

 weight may be applied without producing any deflection, we have a shaft to 

 which we may apply 11,100 lbs. at the periphery of an 18-inch wheel with 

 ■perfect safety, without producing any tortion whatever. Now the power re- 

 quired to turn a mile and a half of screw propeller from a state of rest is 

 1,6001b., which is about one-seventh of the power that may with jierfect 

 safety be applied to the 18-inch pinion, or, in other words, the shafting might 

 be extended to seven times the length I have proposed without being subjected 

 to any torlion whatever." 



It will be observed that it is here assumed that the length of spiral experi- 

 mented upon does not affect the liability of torsion. No iv it may be very 

 true that the half dozen yards experimented upon by Mr. Farrell took 22,196 

 Jb. to twist them, but we question whether a much less force would not have 

 twisted the spiral if it had been 50 yards long. 



" With respect to the power required for this system, it has been shown that 

 1,6001b. applied to the periphery of an 18-inch pinion will be sufficient to 

 overcome the inertia of a mile and a lialf of propeller, and set it in motion 

 round its axis. Now, suppose the pitch of the screw to be 12 feet, then every 

 revolution it makes on its axis impels the train 12 feet, and 154 revolutions 

 per minute will impel the train at the rate of 21 miles an hour; to obtain 

 this speed we require a spur-wheel 5J times the diameter of the |)inion, or 8 

 feet 3 inches in diameter, making 28 revolutions in a minute. If tliis spur- 

 wheel is turned by a 2-feet crank, the radius of the wheel being 4 ft. li in., 

 it follows, that in order to apply a power equal to 1,6001b. at the periphery 

 of the spur-wheel, we must apply twice and ^th of that power, or 3,3001b. 

 to the crank ; this power would be afforded by a condensing engine 24-inch 

 cylinder, 4 feet stroke, and making 28 strokes per minute, or 18 horses power." 



"The foregoing calculations are made without any reference to the provi- 

 sion spoken of for bringing the propeller gradually into motion ; but as such 

 provision is made, and it is known that half the power thai is required to set a 

 macliine in motion is sufficient to continue that motion, we may safely calculate 

 on one-half the power above stated, or 800 lb. as available for the purpose of 

 propelling the trains." 



We quote this passage to direct our readers to the parts mnrked in italics, 

 which will serve to show the accuracy of Mr. Farrell's mechanical notions. 



The following appear to us insuperable objections to the system. 



1st. Taking Mr. Farrell's own calculation that a mile and a half of the 

 screw propeller weighs SO tons, 50 miles of the screw would weigh about 2700 



* The term " Archimedean' 

 a applied in ell book of mech; 

 »ry one acquainted with hjdrauUca ascribes to A'rchimedes, 



, which is becoming very iioi)ular. The term 

 to the tubular pumping screw, the invention of which, 



tons. So that to dispatch a train from London to Brighton not only would 

 the train have to be set in motion, but 2700 tons of metal beside. If there- 

 fore we take the weight of the train at 21 tons, we multiply the load to be 

 set in motion 101 times ! And m every railroad the load maintained in motion 

 would be quadrupled, as it would consist of one length of spiral weighing 

 eighty tons + the train propelled by it.1 



2nd. Engines would have to be maintained in working every three miles. 



3rd. Every engineer knows that the endless screw is a most inefficient me- 

 chanijcal agent, on account of the waste of power which it causes from fric- 

 tion : and it is seldom used except in musical boxes and mechanism of a simi- 

 lar nature. 



4th. The strength of materials must be enormous to prevent a tube a mile 

 and a half long being twisted and broken by a force which causes it to re- 

 volve rapidly. 



5th. Tliere must be great difficulty in obtaining a retrograde motion of the 

 train corresponding to the action of reversing locomotive engines. 



These considerations will, we think, satisfy our readers as to the value 

 of the invention. We cannot help regretting that Mr. Farrell should have 

 spent his time and money in patenting a scheme so hopeless futile. 



BRICK AND TILE MACHINE. 



William Worby, of Ipswich, for '* Improvements in the manufacture of brichs^ 

 files, and other articles from plastic materials." — Granted June 24 ; Enrolled 

 Dec. 1814. See Engraving, fig, 3, Plate IX. 



The machinery represented in the engraving Plate 9, consists of a pug mill 

 a, containing an upright shaft with six or more spirally arranged knives, 

 worked in the ordinary manner by a horse or other power attacbeil to the 

 beam b ; the clay is put into the pug mill through the hopper aperture e, at 

 the top, and gradually driven down to the bottom of the pug mill through 

 apertures into separate chambers (i d rf, on the outside of the pug mill, of 

 which there may be three, four, or a larger number ; each is furnished with a 

 closely fitted piston e, worked up and down by vertical rods /, attached by 

 ball and socket joints at top and bottom, at the top to a cross beam g, wilh 

 a conical formed collar in the centre through which the shaft of the pug mill 

 passes ; on the beam b, there is a small wheel h, which as the beam revolves 

 depresses one piston at the same time the corresponding piston is raised, so 

 that by a complete revolution of the beam b, the pistons in all the chambers 

 are once raised or depressed, at the same time the tempered clay is forced 

 through the openings in the bottoms of the chambers, which are furnished 

 with dovetailed plates to receive dies, or plates wilh orifices of the required 

 form that the clay is to be moulded ; the apertures leading from the pug mill 

 to the chambers are furnished with slides J, regulated by a lever so as to close 

 the opening or any portion of it. The entire machine is supported on four 

 legs. 



Tlie claim is, the so arranging machinery that a suitable pug mill shall 

 have separate cylinders or chambers, each with a piston and moulding orifice 

 combined therevvitl^ by which a succession of bricks, tiles, or other articles 

 may be made. 



CHIMNEY TUBES. 



General George Wilson, of Cross Street, Islington, Middlesex, machinist, 

 for '^Improvements in the construction of chimneys, or Jireplacas generally," — 

 Granted July 24, 1844 ; Enrolled Jan. Ibio. See Engraving, fig. 7, Plate IX. 



Tlie construction of patent stoves, grates, chimneys, flues, &c., under this 

 patent is as follows ;— suppose a register stove made air-tight, instead of the 

 usual fiat or bevil top, has an oval shaped canopy gradually contracted up- 

 wards to a circular tube about 10 inches high, a, with a contraction or swelling 

 inwards of about three inches in the centre of its height, the top of this tube 

 opens into the shaft of the chimney. When fixed the whole of the atmos- 

 pheric air of a room pressing at the focus causes a simultaneous draft, parti- 

 cularly when assisted by the heat of the fire. It has the same effect as when 

 a door is shut, and the whole of the atmosphere pressing against tlie door 

 finds the key hole the means of escape, and the aperture heingsmall increases 

 its velocity. The second improvement is tlie introduction at the back of the 

 grate of a tube i,iperforated with holes to leed the back of the fire with o.xygen, 

 and at the same time assist the up draft and prevent the necessity of blowing 

 or stirring. The contracted tube maybe also introduced at the foot of the 

 vertical chimney of a steam boiler or furnace. 



AGRICULTURAL MACHINE. 



James Vieart, of Chilliswood House, near Taunton, Somerset, Lieut. R.N. 

 for " Improvements in tlie means of obtaining and applying power for working 

 or driving thrashing machines, mills, chaff cutters, and other machines or appa^ 

 ra(«s."— Granted Sept. 12, 1844; Enrolled March, 1845. Hee Engnwinir 

 figs. 8, 9 and 10, Plate IX. 



This invention ccnsists.in the application of the principle of tlie lever to 

 the construction of an engine or machine for obtaining motive power for 



