368 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



[Skptembek., 



another modifiealion of thisjapparatus, which in effect is precisely similar to 

 the foregoing. 



The second part of the invention will be clearly understood by the an- 

 nexed diagram and following description ; that is to say, a a shows a section 

 of portion of a boiler, b ; the safety valve attached by a rod to the lever d, and 

 e the weights ; e is a cylinder attached to the top of the boiler, having a 

 piston/, fitting within it ; this piston has a rod which passes through the end 

 of the lever d, with a collar upon it ; ji; is a syphon passing from near the top 

 of the cylinder below the surface of the water in the boiler, this syphon con- 

 tains a column of mercury equal to the required pressure of steara, the action 

 therefore is as follows, as the pressure of steam in the boiler is increased, 

 should the valve stick in its seat or from any other cause not be raised, the 

 mercury contained in the syphon will be forced into the cylinder e, and a 

 pressure of steam will then be exerted upon the piston /, and the same will 

 be forced against the end of the lever rf, so that a pressure of steam may by 

 this means be applied to the end of the lever d. as well as to the safety valve, 

 ■which cannot very well fail to raise it ; A is a screw plug for letting the mer- 

 cury flow from the cylinder e, back again into the syphon ; the dotted lines 

 show that the syphon may he bent so as to come below the surface of the 

 water, which may be employed for raising the piston instead of mercury as 

 will be understood, for which the inventor claims, first the application of a 

 hollow metal or other proper float in such manner as to act on the safety 

 Talve, and aid in opening the same, when the water in the boiler falls too low ; 

 and secondly, in the application of a syphon pipe with a column of mercury, 

 as before deacribed, to act on the safety valve, and cause it to open the same, 

 when the pressure becomes too great in the boiler. 



ATMOSPHERIC BAILWAT. 



JohK Aitkbn, of Surrey Square, in the county of Surrey, gentleman, for 

 "Improvements in atmospheric railways."— Granted February 24; Enrolled 

 August 24, 1844. 



In the construction of atmospheric railways the air from the traction pipe 

 (as is well known) is removed by means of air pumps, and some difficulty has 

 been experienced in getting out the air so as to obtain a good vacuum, in 

 consequence of the air at each succeeding stroke of the pumps getting more 

 and more rarefied. Now the object of this invention is in the first place to 

 obtain the required vacuum by causing the traction pipes to be filled with 

 water, and then allowing the same to escape through the eduction pipes from 

 "32 to 33 feet" long, by which means a better vacuum can be obtained in 

 the traction pipes than by the aid of air pumps. The object of the second 

 part of this invention is to obtain a more perfect air tight covering for the 

 longitudinal valve of the traction pipe, by covering such valve, and also the 

 pipe « ith » ater for the purpose of retaining the vacuum obtained therein. 



In carrying out these improvements the traction pipe is to have a longi- 

 tudinal opening, which is to be covered with a valve of leather or ether suitable 

 material previously prepared, to resist the action of water in the same manner 

 as the leather employed in pump buckets, and the same may be strengthened 

 by transverse plates of iron, and attacheil by one of its edges to the top Of 

 the traction pipe, or the same may be wholly lifted up, as is now practised; 

 the invention having no reference to the peculiar mode of applying the valve, 

 the principal feature being in the application of water for the purpose of 

 forming a vacuum and keeping the longitudinal valve air tight, which is 

 efl"ected as follows. Fig. 1, shows a transverse section of the traction pipe, 

 w hich is laid in a trough formed between the rails, the whole length of the 

 line, and sufficiently deep to cover the longitudinal valve o, which is some 



inches below the surface of the water ; b h, shows one of the transverse slides 

 or stops, which is received within a rectangular bo.^ or trunk c c, and in order 

 to form a vacuum within the traction pipe, the same is to be filled nith water 

 which is allowed to flow out through any convenient number of eduction 

 pipes, which operation may be performed at any period previously to the train 



Pig. 1. 



arriving, so as to allow sufficient time for the water to run out of the pipe, 

 which after the train has arrived is to be pumped back again to refill the pipe. 

 It will appear evident that as the longitudinal valve is raised, the water con- 

 tained in the cistern or trough will flow into the pipe, and exert a pressure 

 together with that of the atmosphere, on the back of the piston, and assist 

 in impelling it forward, and after the piston has passed each of the transverse 

 sliding stops b b, that length of pipe may again be filled with water, ready for 

 another similar operation. In cases where the railway is to be constructed 

 on ascending or descending planes, the inventor proposes to employ a greater 

 number of sliding stops, and to lift the water by means of pumps into the 

 trough at the highest point, or at various points, so as to keep the longitu- 

 dinal valve always covered, for which he claims the mode of constructing at- 

 mospheric railways whereby water is used for obtaining the necessary 

 vacuum in the traction (lipes, and also for keeping the longitudinal valve air 

 tight, as described. 



IMPROVEMENTS IN STEAM ENGINES. 



John Stetellv, of Belfast, in the county of Antrim, professor of natural 

 philosophy, for " Improvements in steam engines. — Granted March 2 ; Enrolled 

 .Sept. 2, 1844. 



This invention for certain improvements in steam engines, which improve- 

 ments are arranged under nine different heads, consists first in the peculiar 

 arrangement of a complicated condenser, the object of which is intended more 

 particularly as a medium whereby a great amount of heat may be obtained 

 or collected from the steam to be applied to various useful purposes such aa 

 heating the rooms of cotton and flax mills, and supplying hot water to the 

 various branches of such manufacture, than any benefit to the actual working 

 of the engine itself; on the upper part of the condenser, which consists of a 

 vessel somewhat less in capacity than the cylinder, there is arranged two 

 sliding valves for the induction and eduction of the steam at certain parts of 

 the stroke of the piston, this vessel, which is termed the " hot condenser,' and 

 which is intended only to partly condense the steam, is provided with a force 

 pump at its lower p.irt, which impels the hot water collected back again into 

 the boiler and to various parts ot the manufactory as above slated, and re- 

 turns again, at a greatly reduced temperature, to assist in the condensation 

 of steam for the purpose of heating more water ; the valves above referred to, 

 it will perhaps be necessary to state, are intended to conduct the uncondensed 

 steam to a perlect condenser, which we presume is intended to be of the or- 

 dinary construction, as no other is referred to. 



The second improvement consists in the application of a double cylinder, or 

 two cylinders placed side by side, one of which the patentee terms a conju- 

 gate cylinder. These cylinders, which as observed, are placed side by side, 

 have a piston, the rods of which are connected, we presume in any convenient 

 manner, to two cranks placed at different angles upon the same shaft, pre- 

 suming one piston to have performed about two-thirds of its stroke, the other 

 has performed about one third, both of which are travelling in the same 

 direction ; the two cylinders are connected together, and a communication is 

 established between the top and bottom of each of the cylinders, which com- 

 munications can be opened and shut by means of two sliding valves, con- 

 nected together by a rod j the steam parts and valves for introducing or ad- 

 mitting the steam from the boiler into the cylinders not being shown, as the 

 inventor does not deem it necessary ; but, however, steam is to be admitted 

 into one of the cylinders from the boiler until the piston of such cylinder has 

 performed as has been observed, about two-thirds of its stroke, (as near as 

 we can judge trom examining the drawing,) the piston of the other cylinder 

 having performed about one-third of its stroke, at this juncture the steam 

 from the boiler is cut off and a communication is formed between both cylin- 



