388 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[October, 



to lift tliem u\i. There is an interval of about a foot between the range of 

 liaiissi's anil ofcmi/n- liaiisses. 



A tiat bar of iron of the kinil already deseribej, with shifting movement, 

 regulates ilie opening anil closing the foH^/r /(«ussf.s. At each progression 

 of an inch a staple presses and releases the latch, and the correspond- 

 in" conire haiisse submitting to the effort of the current, turns round on 

 its hinges and raises itself to a vertical position, a bridle chain cramped on 

 the solid part of the apron prevents it from going too far. By this method, 

 vhich produces an immediate ellect, is formed a second barrage above that 

 whicli existed before the letting down of the Imusses ; the current remains 

 suspended, the upper edge apposes the (lu«' of water, and allows tlie lock 

 keeper to raise the haiisscs. 



To facilitate this operation M. Thenard has placed on the upper part of 

 each ciiiitre luiusse an iron man-rope, which supports an iron gangway 

 suspended at nearly the same level to which it is intended the retained body 

 of water should rise. 



The lock keeper stands on the gangway, funii.shed with a little portable 

 windlass wliich he rests on the man rope; and catches the haussc witli a 

 hook attached to a rope ; he rolls lliis rope on the cylinder of the windlass, 

 and draws towards him the hauxxc. and with it the prop or slay that supports 

 it against the slipper, and at the same time he books it on to the lanlre haussc. 

 He proceeds thus through all i\\e liciiisst's in succession. When all are hooked 

 he hastens the tilling up of the space between tlie liausses and coiifre liaiisscs by 

 drawing with his band the vent plugs fixed in the roidrc haasses. This done, 

 the latter are balanced by a volume of still water ; the lock keeper then un- 

 hooks in succession each nntre liavsse and abandons it to its weight, which 

 exceeds that of the volume of water which it occupies, to fall down on to 

 the stone work of the barrage, it then latches itself there anew, and the 

 lodv of water is once again held in perfect retention by the hausses. 



These mana'uvres are performed with precision at d quickness. The report 

 of July. 1841, states, that at the barrage of C'oly, which is .57 feet G inches 

 long, with the hausses 2 feet 8 inclies high, two men, in 8 minutes, lowered 

 the hausses, raised the contre hausses, then righted the hausses, and relaid 

 the confer hausses. In this space of time, 16 seconds were suflfieient to 

 lower the liausses and make the barrage disappear, and 20 seconds oiili/ were 

 occupied in raising the euntre h'ausses ami restoring the mass of water in re- 

 tention. 



Tlie report of the Commissioners appointed by the Academy of Science, 

 Belles Lettres, and Arts at Bordeaux, of the 10th January, 1843, states that 

 at the barrage of St. Antony, w hich is 27 feet long, formed by seven hausses 

 of 4 feet Ittng each and .5 feet fJ inches high, and by seven couire hausses; 

 the barrage manonivre was performed twice in 30 minutes — !.f.,in one minute 

 per linear yard of hausses or ciiutre hausses. M. Tbenard tlatters himself 

 that the height of 5 feet li inches is not a liuiit for the application of his sys- 

 tem : be has been obliged to confine himself to this height at the barrage dam 

 of St. Antony owing to local circumstances, he thinks he could carry it to 

 the height of 10 or 13 feet the hausse. 



Already, by practical experience, has he solved a beautiful problem in hy- 

 draulics, which has frequently occupied the attention of engineers, and of 

 which there exists but one other solution, totally ditVerent, it is the work of 

 M. Foiree, Divisional Inspector of Bridges and Highways. 



M. Tlienard has combined in his construction many capabilities which 

 facilitate the working of, and prevent the inconveniences which floating bodies 

 and matters deposited by the current might (tccasion, the consequences of 

 which would be to per[)lex the operations of tlie hausses and the coiitre 

 hausses, he has fixed vent holes in the partitions of the hausses to drive away 

 down the river such bodies as may have been stopped or deposited on the apron. 

 The teeth or elects of the iron bars move in the w birlpools, the entrance to which 

 is closed by grooved traps which render the deposits less abundant than might 

 be supposed. He can remove those which have already formed ihemselves by 

 a pressure and a current produced by turning water through the upper open- 

 ing of the pipe in which it turns the axis of the pinion. To avoid the loss of 

 water which must ensue from openings or interstices of about an inch, which 

 cannot be avoided between t«o consecutive hausses, or between the hausses 

 and the side walls there is placed a little board which covers the joint and 

 hinders the flow. 



Experience has proved that the lelllng down is unattended «itb hurtful 

 jolting, because it is done under a sheet of water which is flowing with ilie 

 greatest rapidity and which instantly deadens all shocks. 



The contre hausses under the trench of water whicli covers them over, 

 seem to hesitate a moment in raising themselves up, under the impulse of the 

 current ; they do not attain any great degree of velocity until in the last 

 portion of their movement, the acceleration is greatly modified by the mass of 

 water the rontre hausses already raised up send back laterally against the 

 others. Up to the present time there has not been any serious difliculty ex- 

 perienced in performing the manoeuvres; branches, weeds, gravel and sand 

 which might interfere with them are easily dragged away or removed. 



It is easy to conceive that within certain limits hausses and eonire hausses 

 of a greater height than 5 feet 6 inches, can be employed and worked. 



It is the work of experience and time to pronounce upon the preservation, 

 keeping in repair, and replacing the moveable parts, under and out of the 

 water, of which the apparatus of M.Thenard's barrage is composed. It is 

 under the proof of ice formed underneath, raised to the surface and carried 

 away by the current, against the hausses, that we can judge definitively of the 

 power of resistance in the actual constructions and the modifications that 

 may be applied to them. We can rely with confidence on the skilful perse- 

 verance of M. Thenard to ward off any inconveniences that have not as yet 

 presented themselves. 



In the mean time, the barrages-mnbHes, such as are executed at St. Antony, 

 reflect honour on the inventive talent of M. Tbenard ; they appear to be sus- 

 ceptible of numerous and important applications, and to justly the appro- 

 bation that the Committee of Mechanical Arts deem ihemselves empowered 

 to give, and recommend the Council of the Administration to award to them. 



The Committee proposes, besides, to insert in the Records of the Society 

 the present Report, as well as the drawings and ileseriptious which accom- 

 pany M. Thenard's memorandum. 



Explanations of the Figures and Plans. 



Fig. 1. Plan of the Barrages-mobiles, or wier with moveable flood-gates, 

 with all their appendages, one set of the hausses or gates is thrown down. 



Fig. 2. Transverse section of the same on the axis of one hausse and contre 

 haus.i^c on the line X X of fig. 1. 



Fig. 3. Another transverse section, the haiisse and contre hausse being 

 down on the line Z Z of fig. 1. 



Fig. 4. Section of one of the slippers, upon which slides the support of the 

 contre hausse. 



The same letters represent the same objects in the figures of the two plans. 



A. The left-hand gangway where the lock-keeper regulates the opening 

 and shutting of the /<ni(S,?i's. 



E. Radiated mason work, or apron, under water, in which the lower por- 

 tion of the barrage is fixed, 



C, D, D'. Sills of strong oak beams grooved into the apron, on which they 

 are fixed by as many iron cramps as there are gates or hausses-mobiles. 



K. V. (i. Three gales, or hnusses-mobiles, raised by a quarter revolution round 

 3 pair (tf horizontal hinges, a a, fixed on the sill C. These three gates, 

 slightly incline down the river, as shown in fig. 2, and are supported in this 

 position by three strong legs with binges, b b b. 



H, I. Two g;Ltes, or contre liaus.ses-niohites, lying on the apron. 



/), five strong stays fixed to hinges upon the lower face of thu hausses, E, F, 

 G, to sustain them when they are raised against tlie pressure of the water 

 retained by these gates. 



c, c, c, c, c. Five slippers fastened with cramps upon thestone apron, and in 

 each of which is inserted a short thick piece of iron close to the feet of the 

 iron stays or supports b, besides a groove, along which groove these stays 

 glide and allow the gates to drop down when the teeth or elects d, of the 

 longitudinal bar J, wdiieh is put in motion by the windlass K, has pushed 

 the stays aside into the groove ii, furnished with fillets o, on each side as 

 guides. 



J. A flat longitudinal bar, fixed upon the apron above the slippers and above 

 the feet of the stays which support tlie gates when they are raised. This 

 bar has as many teeth or elects d, d, d, as there are stays, so that at each 

 horizontal movement that it makes when drawn by the windlass E, towards 

 it, it displaces first one stay, and that the farthest off, and then the others 

 in succession, till all the gates are down. 



K, K. K. Three raised contre hausses or gates, alike to, and corresponding 

 with the gates or hausses, E,F. G, each contre hnusse is retained in its vertical 

 position, against the pressure of the water, by a double chain/. 



Tlie contre hausses, lying over the lower chambers of their chains, are re- 

 tained in this position, against the eflorls of the current which tends to raise 

 them, by a lalch and spring, placed unrler a chin solidly fixed on the sill of 

 oak iron tie bar bound to the slakes or piles L, L, L. 



f,.f,f. Three double chains lixed at the upper part of the apron, each has 

 a ring fasteneil on one of the stakes, L, in order to retain, against the pressure 

 of the water, the raised contre hausses. 



The stakes, L, of oak, are boiled to a horizontal timber sill or spring to 

 render them solid, ihey traverse the apron and are bolted below to a frame 

 of timber, as appears in the section, fig. 2. 



M M. Five other similar stakes united with the preceding ones by the iron 

 ties, g g. 



N. A fiat bar of iron moved by a windlass longitudinally by means of teeth 

 cut in the extremity of the bar working into a pinion fixed at the foot of an 

 iron axis which is turned on tlie top by a small capstan. There are as many 

 teeth as there are bolts in the conire hausses, \l disengages them one after 

 another as the bar draws the elects against the latces the current of water 

 then raises the contre hausses in succession side l)y side to form a temporary 

 barrier and also facilitate the raising ol tbe hausses that are down. 



0, 0, 0. Three gangways of iron, hung on hinges and by two little chains 

 P, i, to two iron stanchions e, fined and bolted on the upper border of each 



