;jO() 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



I'Septkmber, 



head, aljovc the termination of the air-pipe a a: it is there met by the 

 ascentUn"- c-nnent or stream of air; it is dispersed into drops, and 

 carried up by it, in tlie manner lierein-before made linown. 



It slioiild ije stated tliat, in mines, and otlier deep places, where the 

 water may accumulate and rise to some height in the pit or shaft, 

 from the stoppage, bv accident or otherwise, of the steam-engine, 

 water-wheel, or other prime mover, or from other causes, I introduce 

 a stop-cock, or other contrivance adapted to the purpose, to regulate 

 the passage of water into, or to exchule it from, the pipe h h. 1 effect 

 this, bv putting the apertures aforesaid, in connexion with, and in 

 making them receive their supply of water from, a pipe to which such 

 stop-cock is applied. I attach to this stop-cock, or other contrivance, 

 a rod of wood or metal, of sufficient length to rise above the surface of 

 any water that thus may accidentally accumulate in the shaft or pit, 

 and of sufficient strength to enable tlie workman to open and shut the 

 aperture of the stop-cock, or other contrivance, by it. 



It is essentially necessary that this should be attended to, as other- 

 wise the water, or other lifpiid, may accumulate aiwl rise to such a 

 height in the pipes a a, bh, as may prevent the passage of the air 

 from the pipe a a into the pipe h b, and thereby stop the action of the 

 apparatus. For a similar reason, the water or other liquid must never 

 be allowed to stand at a higher level above the end of the pipe a a, 

 than the pressure of the condensed air can displace ; and to effect this, 

 the reservoir c c must be so proportioned to the lower part of the pipe 

 b h, that whatever number of inches the water or other liquid may 

 descend by the pressure of the air in the one, it may ascend to an 

 equal number of inches in the other, as in the two limbs of a syphon 

 or bent guage ; and to guard still further against the chance of any 

 interruption of the process, either by an accumulation of water in the 

 mine, as aforesaid, or by an imperfect state of the stop-cock allowing 

 a portion of such accumulated water to flow past it into the lower 

 parts of the pipes aa,bb,\ connect with the lower parts of such pipes 

 a small pump, to be worked by the hand of a workman, and rising 

 sufficiently high in the mine to be above the surface of any water that, 

 perchance, may thus accumulate. By such ])ump, the workman, 

 labouring but a few minutes only, will be enabled to withilraw the 

 water or other liquid from the pipes a a, bb, and such liquid will be 

 discharged by him, not at the top of the mine, or at the adit, but back 

 again into the shaft, that it may be subsequently raised by the ascend- 

 ing stream of air. 



In applying my invention, in practice, I sometimes cause the water, 

 or other liquid, to flow into the up-caal pipe, in any given time, in 

 direct proportion to the quantity that can be carried up it, in that 

 time ; which may be elTected by duly proportioning the sizes of the 

 apertures or ])erforations, or by the adoption of regulating stop-cocks ; 

 and in other modes of applying it, I cause the air, after it has passed 

 through the down-cait pipe, to be distributed and dispersed under a 

 large surface of water in a confined chamber, or reservoir, that it may 

 take up a portion of the water by adhesion, in the same way that water 

 is taken up in the formation of steam, — excepting that, in the one case, 

 the water is taken up by the air ; in the other, by caloric. 



The air and the water commingled with it, or that quantity which is 

 thus taken up by it i» the state vf rapot/r, is then allowed to accumulate 

 above the surface of the solid body of water confined within such 

 chamber or reservoir (assimilating in its object to a boiler for the 

 generation of steam), until it attains the same pressure, per square 

 inch, as the air flowing down the down-cast pipe. After which, it 

 is allowed to flow through a pipe, extending above the surface of the 

 liquid in such chamber, into the lower part of the pipe, where it 

 meets with, disperses into drops, and carries up a still further quantity, 

 in the manner hereiu-before described. 



The weight of water in the pipe, b b, at any one time, must be le--s 

 than the pressure given out by the ascending current of aii. 



At the top of the up-cast pipe, b b, I cause the air and water taken 

 up by it, to be received into a dome, or other appropriate chamber, 

 that the greatest portion of the water may be collected together again 

 in a body, and thence be allowed to flow freely away. The air, and 

 that portion of the water still retained by it, is also allowed to esca))e. 



lu other modes of raising water b\' my improvements, as aforesaid, 

 I produce and maintain, by any of the mechanical means adapted to 

 the end, a partial vacuum in the pipe, b b; and instead of employing 

 a down-cast pipe, a a, to convey condensed air into the pipe, b b, i 

 allow air to flow into it from the mine, through pipes arranged for that 

 purpose ; so that, by the difference of pressure between the air in the 

 mine, and that in the pipe, b b, the water may be carried up by an as- 

 cending current of air. 



Another important feature of tliis invention is, that the ventilation 

 of a mine may be carried on free of charge. For the fan or fanner, or 

 blowing cylinder, may be made to receive its air frcm the open atmos- 

 phere ; or, by means of pipes extending to the required distance, the 



air may be received from the depths of the mine ; or without enq)loy- 

 ing pipes, it may be received from the upper part of the np-ciist 

 shaft of a mine, which must be domed over for that purpose. By 

 which mode of operation, the impure air of a mine may be withdrawn, 

 that pure atmospheric air may descend the shaft or pit, by its gravitv, 

 to occupy its place. 



Having thus described the nature of the invention, and the manner 

 in which the same may be performed and carried into effect, I wish it 

 to be understood, that the velocities of the air, as due to given pres- 

 sures, and the descending velocities of drops of rain, wiien falling 

 througli the atmospliere, are given by me as approximative uumbers 

 only: for atmospheric changes, and otlier causes, will produce a mate- 

 rial variation from tliem. And I wish it to be further understood, that 

 I tfo not, in this patent, confine myself to tlie precise arrangements and 

 dispositions of the combinations and contrivances herein described, 

 and shown by the engraving ; but I avail myself of all such other com- 

 binations and contrivances as in mechanics are equivalent thereto. 



ADDENDA. 



By some persons it is supposed, that air cannot be made to flow 

 through pipes of great length. — This supposition has been produced 

 by a statement made in Dr. Robisoii's ".Witural Pliilosop/ii/," art. 

 "Pneumatics," respecting an experiment conducted, many years ago, 

 at an iron-foundry in Wales. — It is there stated, that an engineer 

 erected a machine, at a powerful fall of water, to work a pair of blow- 

 ing-cylinders, or cylinder-bellows, the blow-jiipe of which was con- 

 ducted to the distance of a mile and a half, where the delivery-pipe, 

 or tui/ert, was applied to a blast-furnace in the usual manner. But 

 notwithstanding that every precaution was used, in making the pipes 

 as smooth as possible, the experiment failed ; and the failure was 

 ascribed to the impossibility of making the pipes air-tight. — Other 

 persons, since then, have ascribed the failure, with much better judg- 

 ment, to the friction of the air against the sides of the pipe ; but, being 

 unacquainted with the laws which regulate the passage of fluids, have 

 thence fallen into the erroneous opinion, that air cannot be made to 

 flow through pipes of great length. 



I am not acquainted with the sizes of the pipes employed by the 

 engineer in Wales ; but it is certain that he was wholly ignorant of 

 the subject, and that the pipes were not properly proportioned to the 

 length. His ignorance is shown by the following: — 1, by his making 

 the pipes as smooth as possible in the bore; 2, by his expecting to 

 get the same, pressure of air from a pipe a mile and a half in length, 

 as from a short pipe ; and 3, from ten minutes of time elapsing after 

 the action of the piston in the blowing-cylinder had taken place, before 

 the least wind could be felt at the end of the pipe, whereas he had 

 calculated that the interval wou'.d not exceed six minutes. 



With the view to elucidate these errors, and consequently to expose 

 the ignorance of tlie engineer, I shall adduce the following : — 



1. It is well known to those who are acquainted with the flowing 

 properties of air, that providing there be no sudden enlargements and 

 contractions in the pipes, it is a matter of comparative indifl'erence 

 wdiether the pipes be smooth in the bore, or left in the rough as when 

 cast. For the tleliverv under the same length of pipe, under the same 

 pressure, whatever that length may be, is, as nearly as possible, the 

 same in both cases. 



•2. That the greater the length of pipe, the greater, under certain 

 definite proportions, must be its diameter, in order to overcome the 

 friction, and to deliver, under the same amount of pressure in the 

 blowing-cylinder, a given quantity of air in a given time. Hence, as 

 the diameter, and consequently the area of the pipe incrcasts, the 

 pressure of the air must decrease in a correspondent proportion. 



3. That atmospheric air, however compressed, and therefore under 

 whatever pressure it may act, cannot, jiractically, flow with the rate of 

 speeil assigned bv him, that is, 1320 feet in a second, ei'en into a va- 

 cuum ; much less through pipes a mile and a half in length, and under 

 the moderate amount of jiressure, which is tlu'ee pounds per square 

 inch, used, commonly, in blast-furnaces. 



To illustrate this still further, and to show how easy it is for persons 

 unacquainted with these subjects to fall into error, and thence to de- 

 duce erroneous conclusions, i will suppose that 3000 cubic feet of air 

 per minute, at three pounds pressure per square inch beyond the 

 atmosphere, had to be driven into a blast-furnace ; and that "the engi- 

 neer, in Wales, finding that a pipe Ij inches diameter, when only from 

 a foot to a foot anil a half in length, would ileliver that quantity, had 

 jnit down a pipe of twice that area, or G inches and four-tenths in 

 diameter. 



The quantity of air, per minute, that would have been discharged 

 through that pipe, when of different lengths, and under the same 

 amount of pressure in the blowing-cylinder, would have been as 

 follows : — 



