1841.] 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



1.37 



is ther, reversed, anil the gates closes, retaining all the water that has flowed 

 i)ast the embankment. To open the gate, and discharge tlie water en masse. 

 various methods might tie adopted. The simplest, perhaps, w ouUl be to draw 

 up out of the larger leaf a paddle of siiiiicient ?ize to make the smaller leaf 

 e.xpose a greater surface to the pressure of the water, when, of course, the 

 j.;ates would (jpen by the down-stream j/ressure, as they would m the other 

 ease by the up-stream pressure. The paddles may be worked by self-acting 

 lialauce weights, or by a water wheel set in motion by the fall of the tide, so 

 as to make the whole self-acting. The water, after its discharge, may be 

 directed by proper jetties into the channel required. 



Over the intermediate space of sand and silt, betwixt rock ,ind rock, I 

 would projiose an embankment composed of rock and earth in the manner 

 shown in the drawing ; the centre of the bank of pu:ldled earth or clay : and 

 the outer parts of rock faced with heavy squared pitching brought up from 

 low w ater in a curved manner, as shown in the drawing. In order to secure 

 as far as possible or necessary the water tightness of the bank, I would re- 

 i ommend a r>w of sheet piling perhaps 2.5 or 30 feet deep on each side of the 

 puddle wall in the centre of the bank, and at the foot of each slope another 

 row of sliorter piles, to prevent the pressure uf the hank forcing out or blow- 

 i.ig up the sand foundation. 



A carriage road to be formed over the whole, passing over the locks by 

 draw or swivel bridges, and over the sUiices by stone or wooden arches. 



This plan, with 15 feet of water impounded, would alTord a sectional area 

 of discharge of .3,970 square feet. The calculations in my report are made 

 upon an area of 2,400 square feet only, so that, if by that amount the scour- 

 ing power w'as trebled, it would, by u.sing all the means which the locks and 

 sluices of the plan just detailed alTord, be increased more than seven-fold. 



At a ten feet tide at Runcorn, the sectional area of the stream is now about 

 O.fcOO square feet. The locks and sluices would afford p.i the same height 

 about 4,120 square feet. Although this is less than half the present sectional 

 area, a difference in level of considerably under a foot would so increase the 

 velocity through the sluices as to pass the same quantity of w iter. 



WARMING BUILDINGS BY HOT WATER. 



The subject of warming buildmgs by hot water having lately excited a 

 more than ordinary degree of interest, owing to the recent disastrous tire at 

 Manchester, we lay before our readers a report made to the Manchester Fire 

 Assurance Company, by Mr. John Davies, M. W. S., and Mr. G. V. Ryder. 

 (We shall continue the subject in our ne.xt.) 



•• Befoie we proceed to detail the experiments which we have made, we 

 shall briefly describe the appearances observed, and the information obtained 

 at a few of the principal places which have been visited. We shall then be 

 enabled not only to coafirni but to extend the statements in Mr. Ryder's tirst 

 report. 



It has been found, on inspection, that Birch Chapel has, at various times 

 since the occurrence alluded to in the former report, sustained much damage. 

 Wood, matting and cushions have, in a variety of places contiguous to tlie 

 hot water pipes, been charred to an alarming extent. 



With respect to ilr. Barbour's warehouse, farther inquiry has fully corro- 

 borated the previous statements of its having been on fire, close to the pipes, 

 at different times and in different places. 



Of the Unitarian Chapel, in Strangeways, tne dire ;tors are already in pos- 

 session or information from both ilr. Ryder |and Mr. Rawsthorne, and this 

 information seems to leave no doubt as to the injury which has residted 

 from the use of Mr. Perkins' hot water apparatus. 



The heat in the Natural History Musciun having been repeatedly stated to 

 vary in different parts of the pipes, aTid to become, in some cases, the great- 

 est at places remote from the furnace, the fact has been confirmed by our 

 own observations, and by our subsequent experiments. As this circumstance 

 has excited much interest, and been generally questioned, we shall preseutly 

 endeavour to assign the cause. 



Tlie apparatus, which it may be proper to notice in reference to its general 

 form and construction, consists simply of a long, endless iron tube, carried, 

 in different directions, from a furnace to which it returns, and in which about 

 one-sixth of the whole length is inserted and formed into a coil, so as to be 

 Miftieiently exposed to the action of the fire. The tube is, at the commence- 

 ment, filled, or nearly filled, with water, which, by the application of the 

 heat, soon begins to circulate, and, in that way, to impart an increase of tem- 

 perature to the apartments which it traverses. The diureusions of the pipes 

 are such, that, on the average, eleven feet in length will contain ojie pint of 

 v.ater. Connected with the principal pipe arc two others, wliich are opetied 

 by a screw, one to allow for the ultimate expansioii, and both subserrieut to 

 the introduction of water. 



.Vs far as lay in our power, we have made such experiments aa occurred to 

 I. J, repeatedly, and under every variety of circumstance. 



Not having any instruments which would furnish speedy and adequate 

 criteria for the determination of high temperatures, we have resorted to the 

 i.uiar.imation of combustible bodies, and the fusion of others, depemling on 

 tl'.c recent and high authority of Professor Graham for the degrees which 

 they indicated. H '--''■ ■•^.ViJ 



The ordinary method liitherto resorted to for ascertaining high tempera- 

 tures in the pipes, is to file a small portion perfectly smooth, and observe the 

 progressive changes of colour which occur. We did not neglect this expe- 

 dient ; and we witnessed, to great advantage, the successive and beautiful 

 tints. As the temperature increased, we were presented first with a straw 



colour, then a deep bluish purple, and, (inally, with a dark silvery hue. The 

 first is said to indicate 150°, and the blue 600". 



In the Natural History Museum we applied our tests, but were enabled to 

 do so only to a very limited and unsatisfactory extent. Mr. Walker, the |)ro- 

 prietor of the patent right for Manchester and the neighbourhood, accom- 

 panied us to the establishment of Messrs. Vernon & Company, engravers, 

 where we had the opportunity of trying the system rather better, but still 

 imperfectly. Finally, Mr. Walker acceded to our request to have put up, on 

 his own premises, a suitable apparatus, which was to be submitted entirely 

 to our control. It consisted of an inm ])ipe upwards of 140 feet in length, 

 25 of which were coiled in the furnace ; 20, at least, being freely exposed to 

 the full action of the fire . 



lu addition to the apparatus, as at first fitted up, we had a branch pipe 

 and a stop cock, whidi enabled us, by cutting off at pleasure a great portion 

 of the circulation, to perform oiu' experiments on a contracted scale, and 

 under a variety of modifications. 



Mr. Walker, being from home at the time, placed his foreman entirely 

 under our directions, so that we had the opportunity of i)ursuing tlie investi- 

 gation to any extent which we might think proper. It is but justice to state, 

 that this person rendered, very willingly and with much practical skill, all the 

 assistance which was required. 



The apparatus having, on Friday the 5th ult., been fitted up and found 

 on triiil, to be in proper condition, the experiments were commenced on the 

 following morning, at ten o'clock, when the apparatus had arrived at a suit- 

 able state. 



I. First class of e.rperimcnts, viz. those made with the whole length. 



1. The pipe from the furnace became very soon sufficiently hot to singe 

 and destroy small feathers resting upon it. 



2. Speedily afterwards, the same pipe exploded gunpowder. 



3. (Ju the highest pipe, within a foot of the expansion pipe, bisnuith was 

 readily melted, denoting a temperature exceeding 470'^. The pressure at this 

 Ijoint must have exceeded 35 atmospheres, or above 525ft. on the square 

 inch. 



4. Feathers were singed instantly, aud matches lighted, at the same place. 



5. Gunpowder inflamed readily in various parts of the flow pipe, and on 

 the expansion pipe. 



6. Blocks of wood, of five different species, were charred : from the dea 

 ^vood the turpentine issued profusely. 



7. Other combustible materials were also severally much charred. 



II. Class of erperiments, with the shorter circulation. By this cliange a 

 greater pressure was immediately observable, as tlie expansion pipe end seoera 

 of tlie joints emitted steam, and admitted the escape of water. 



1. Cane shavings, on the pipe above the furnace, readily inflamed. 



2. Lead melted at the same place ; and the temperatiu'e must, therefore, 

 have exceeded 61'2^. Making a rough calculation from the table of the French 

 Academy, which does not extend beyond 50 atmospheres, I take 612' to re- 

 present 75 atmospheres, or about 1,12516 pressure on the square inch. 



3. Diflereut wood shavings inflamed on the upper pipe. 



4. Cotton ignited freely at the same place. 



5. Matting inflamed at the same place. 



G. Cotton, hemp, aud flocculent matter, collected from Mr. Schunck's fus- 

 tian room, ignited on the returning vertical pipe. 



7. The blocks of wood, tied to different parts of the tube, were much acted 

 upon aud charred in a very short time. 



Observing the expansion pipe to be in a state of considerable agitation, and 

 warned of an explosion, the temperature was reduced, and the experiments 

 were, for the time, suspended. 



The pijies having, before three o'clock, been refilled aud screwed u]), for 

 the express piu'pose of an explosion, the following experiments were made in 

 the progress of the preparation : — 



1. Mungeet was readily ignited. 



2. Difterent sorts of paper and pack thread were destroyed. 



3. Bismuth fused instantly. 



4. Cotton inflamed. 



5. Sheep's wool became speedily charred, in 2" or 3" after the stop-cocfc 

 closed. 



6. \i five o'clock the sheet lead, affixed to the upright pipe, freely melted ; 

 steam issued violently from the bend in one of the upper horizontal pipes, 

 and, in three minutes afterwards, the explosion occurred iu the furnace pipe, 

 at the top of the seventh coil, which presented, on subsequent examination, 

 a lateral aperture about two inches long and about one-sixteenth of n:>. inch 

 broad. 



In the lapse of two or three minutes after the commencement 'f the ex- 

 plosion, the furnace was entirely emptied of its contents, which were pro- 

 pelled, iu a divergent direction, like one mass of fire, so as almost to fiU the 

 apartment. The force with which the ignited embers rebounded from the 

 opposite wall, and other obstructions, occasioned them to scatter in profusion 

 like a shower of fire over evei-y part of the place. The noise was so great as 

 to bring to the spot a multitude of people from the adjoining streets. A 

 number of articles in the shop — as, for example, packing clotli, paper, and 

 hemp — were subsequently found to be on fire in different parts of the pre- 

 mises. 



These appearances, aud their immediate effects, seem to have been precisely 

 slniilar to those which are said to have been witnessed at the explosion iu the 



