42 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[Februart, 



mixed witli sand was used instead of limo ; g- is a piece of Memel 

 timber, 3 feet long, 6 inches wide, and 1 1 inches deep, representing 

 part of a girder, having an interval of one inch between the end of it 

 and I lie partv wall ; ; is the iron strap, 3^ feet long, 25 inches wide, 

 and ' inch thick, bolted to tlie girder g, and passing throngh, and ex- 

 teniling beyond the wall to within one inch of the no/zle n, of the tew 

 iron iilMlie'bellows. One foot fonr inches of its lenglli was exposed 

 to (he lire, which was lighted at ten o'clock a.m. 



Bv eleven o'clock the" tire was in good action thronghont ; the coals 

 were well heajied over and about the iron strap to witliin ."> or U inches 

 of the top of (lie wall, and the heat was kept up to the greatest prac- 

 ticable intcnsitv, bv (he miinterrnpted action of the bellows, till four 

 o'clock P.M. 



It was one o'clock before that part of the iron strap in contact with 

 the girder became too warm, even close to the wall, to render it ne- 

 cessaiy to withdraw the hand from il, and even at fonr o'clock, by 

 wliich time 5 inches of the end nearest the tew iron were burnt com- 

 pletely away, there was not sulheient heat in any part of it outside the 

 parly wall, either to discolour dry wood shavings or paper, or to ignite 

 naptlia. At G inches from the wall the hand could be continued on 

 the iron without inconvenience during the whole period the experi- 

 ment occupied, and at no time was the party wall red hot. 



There can be no doubt but that the lire 'might have been kept up 

 long enough to consume the whole of the iron sniTOunded by it, with- 

 out snflicient heat being communicated to the girder to set lire to it. 



The bulb of a thermometer (hat happened to be at hand, was ap- 

 plied to the iron, where it entered the party wall, but the degree of 

 heat couhl not be determined, as the tube extending only to US 

 degrees of Fahrenheit, was very soon filled by the quicksilver, and was 

 then willidrawn to prevent it from bursting. 



The cement mortar in the joints of the brickwork nearest to the 

 lire was reduced to dust. In this state. Colonel Pasley oidered some 

 balls of it to be mixed up with water, into the consistency of a stiflish 

 paste, which set rather slowly, but in the course of a few days became 

 extremely hard, in consequence of the cement having been calcined 

 by the fire, and thereby restored to the same state, in which it had 

 been received from the manufacturer. 



BALANCE GATE.S. 



Erected at the JForks of (he East London Water WorU Company, 

 Old Ford. Exgixeer, Thomas Wicksteed, Esq., M. Inst. C.E. With 

 two Engravings, Plates II. & III. 



In (he year 1633, the East London Water Works Company made 

 very considerable alterations and additions to their works, by cutting 

 a canal for the purpose of bringing the water from a higher part of 

 the river Lea, near the Lea Bridge Mills, to their works at Old Ford, 

 and to guard against any deficiency of water for the working the mills 

 on the river Lea, and to satisfy the owners of the mills, the Company 

 agreed, in the Act of Parliament authorizing them to make the altera- 

 tions, to form a large compensating reservoir covering about 1*1 to 15 

 acres of land, with two entrances, one at the south-east corner of the 

 reservoir, near to Old Ford Lock, where there is erected a pair of 

 tide or flood-gates, for the admission of water only as the tide rises, 

 and another entrance at the eastern corner of the said reservoir upon 

 the banks of the river Lea, above the City Mill Point, consisting of 

 three openings with six balance gates, for the admission of water from 

 the river, and for discharging the water 'out of the reservoir into the 

 river for the use of the millers. As the tide flows up the river it fllls 

 the reservoir, and when the tide ebbs, if required by the millers, the 

 water is allowed to run out into the river, anil thus compensate them 

 for any quantity of water that might be abstracted from the upper 

 jiart of the river for the purposes of the company. 



It is our present object to confine ourselves to the description of 

 the Balance Gates, which are well deserving of notice by the jirofes- 

 sion, and to point out where they difler from the Dutch system of 

 construction. 



As the neap tides at the point of delivery rise only, on some occa- 

 sions, a few inches, and as consequently a very large quantity of water 

 might have to be delivered in a very short space of time, with so low 

 a head or pressure, a great width of outlet became requisite ; if the 

 ordinary sluice gates had been erected, the time required to open 

 them would have been above an hour anil a half, and consequently the 

 whole of the water might not have been returned into the river before 

 the preceding low water; whereas the balance gates, as we can bear 

 witness to, are easily opened or closed in ten minutes, against a pres- 

 sure of water. 



The essential diflerence between the gates designed by Mr. Wick- 

 steed, and the old Dutch balance gates as described in Belidor's 

 Architecture Hydraulique, is this — the old gate is larger in area on 

 one side of the centre than the other, on the largest side a sluice gate 

 is introduced, which when opened reduces the area of the largest side, 

 so that it becomes less than the other, which was before tlie sluice 

 was opened, largest; by this arrangement when the sluice gate is shut 

 the pressure of the water iqion the largest area causes the gate to re- 

 main closed, but when the sluice is opened the greatest pressure is 

 upon the other side (or ha!/) of the gate, and causes it to open hut 

 not cunrplttely, and tackle must be made to open it wide. In Mr. Wick- 

 steed's gates the sides are of equal area, and they are made to open 

 at once by a toothed quadrant and pinion; two gates are also intro- 

 duced in eacli opening, and set at an angle which gives strength to 

 their construction and saves masonry. When the gates are closed, by 

 the application of a very ingenious contrivance, consisting of a verti- 

 cal iron shaft fixed in the hollow quoins, with three eccentrics or cams 

 upon it, they are made to close against each other, and against the 

 cills and recesses in the side walls, so that no leakage whatever takes 

 place. 



These gates are, we believe, the only ones of the kind erected in 

 the kingdom, and when we were favoured with a view of them, they 

 had been in use for six years and in excellent working order, they had 

 not been repaired since they were first erected by Messrs. Hunter and 

 English, of Bow, whose reputation as millwrights is so well known, 

 that they needed not this accession to their fame. 



The cost of the gates we could not ascertain, as tliey were done in 

 conjunction with other works by contract, but we can easily give credit 

 to Mr. Wicksteed's statement that the expence was not more, if so 

 mucli, as common sluice gates with their elevating machinery, founda- 

 tion, &c., when it is considered how many sluices there must have 

 been to insure the same width of opening. 



These gates are different in construction, and are used for a different 

 purpose to those erected some years since at Lowestoff; w'ith the ex- 

 ception of these two instances, we are not aware of any other gates 

 erected upon the Dutch principle in England, but we think there are 

 many cases in engineering where their introduction might be advan- 

 tageous. 



The following additional particulars we select from the contract 

 and specification of the work, which will together with the engravings 

 give an accurate view of their construction. 



" They (the Balance Gates) ai-e different in coustruction to the common 

 flood-gates ; a description of one gate will answer for the whole : the gate is 

 made to work upon a vertical shaft as a centre, and is equal on each side 

 thereof. One gate, when closed, shuts against another gate on one side, 

 while the opposite sides close against a recess in the piers or side walls. It 

 mil appear evident, upon an inspection of the plans, that the gates being 

 equal on each side of the vertical shaft, which is the centre of motion, what- 

 ever pressure of water may he against them, that there is as great a tendency 

 to keep the gate closed as there is to open it, and that being, under any cir- 

 eninstances, eqcially balanced, a very slight exertion of power (suflicicut to 

 overcome the friction of the working parts) will either open or close them. 

 When the gates are closed, and it is desirable to retain the water in the 

 reservoh, to destroy the effect that any vibration might have upon them to 

 cause a leakage, a shaft is introduced upon which three eccentrics are cast, 

 which, when applied to tlie gates, pinches them against then- abutments, and 

 thus jirevents any leakage that might by possibility occur. When it is de- 

 sired to open the gates to discharge the water of the reservoir into the river, 

 the eccentric is first to be worked so as to take off its effect upon the gate, 

 and then the quadrant and pinion must be worked to open the gate, whieli, 

 as the pressure of water is equal iu its action iqion both sides of the centre, 

 will be a matter requiring hut a small exertion of power. 



Description of the JJ'oi-k. — The framing of the balance gates is to be of 

 good EiigUsh oak timber; the planking to be the best Memel plank. All 

 the joints are to be made sound and good ; the mortices to be cut oat square 

 their whole depth, and the tenons to he made so that they shall fit equally 

 over even,- surface; the hutfing joints to be squared so as to tonch and bear 

 equally over the butting surface. Wherever the timbers are framed into the 

 iron-work, the iron-work shall be made true and good to receive it, so that 

 it shall bear equally on all the surfaces ; and wherever VM-ought iron straps 

 ai-e let info the timbers, they shall he fitted accurately; no packing will be 

 permitted, but the iron must fit fairly and strictly to the wood. AU keys 

 and bolts for straps, and cast iron work must be made to fit accurately, so 

 that the holts fill up the holes made for their reception, without shaking or 

 depending, upon the friction of the head and nut. 



The timbers are to he rebated for the reception of the ends of the 2-iiich 

 fir planking, so that when tlie planking is introduced, the surfaces of the 

 planking and timbers shall be flush — the planks are to be 2 inches thick and 

 !) inches wide, to be laid diagonally, as described in the drawings ; at the two 

 ends, and wherever there is a cross or diagonal timber, the plank shall lie 

 fastened thereunto by means of 2 screw bolts at ereiy bearing, and wherever 

 iron intervenes between tlie planking and timber, it shall be drilled, and the 



