i02 



THE CIVIL ENOINEER AND ARCHITECT'S JOURXAL. 



[Jl'LV, 



iKiIly; tliis sliet'liiifi: to be firmly spiked on at riiflit angles to the 

 ]iilfs; the lioi(;ht of the cappiiifj-pieres ahove the bottom of the 

 culvert will necessarily he governeil by circumstances which we 

 cannot anticipate; sufficient waterway in all cases should be left. 

 A\'here the bottom of tlie watercourse is remote from the gravel 

 line, it will be necessary to floor the bottom of the culvert to pre- 

 vent its being choaked by the rising of the bog, the effect of pres- 

 sure on the sides. Cross pieces should be carried from opposite 

 )iiles, as at top, and on these the planking should be spiked to pre- 

 vent the floor lieiug forced up. Slieeting piles may be driven at 

 the upstream end if necessary, to prevent the water running under 

 the flooring. 



The principle here suggested has this additional advantage, that 

 it will admit of the deepening of the watercourse for drainage 

 purposes, without detriment to the efficiency of the conduits. In 

 cases where a waterway of 2 or 3 feet in Ineadth is sufficient, hur- 

 dles may be substituted for the sheeting of the top and sides. 



R(ii/iciii/s in Brnj. 

 The subject of Railway making through bogs being very little 

 understood, we propose the fidlowing system in preference to 

 throwing in earth to replace the jieat, an operation which may be 

 extremely e.xpensive if tlie material be remote, and the bog deep 

 and wet, for a complete embankment must in that case be made, 

 whose base will rest upon the gravel or clay at the bottom; it 

 would, in fact, be tantamount to embanking through a lake, as the 

 light wet peat, instead of being compressed, would be forced up 

 on all sides by the heavier material. I 



The same preliminary operations being performed as for common | 

 roads — namely, side and catch-water drains, at the prescribed dis- 

 tances, and forming the bed or seat with dry peat well chopped 

 and trampled, we recommend, if the bog be wet and deep, and 

 time cannot be allowed for drainage, that a layer of fascines, 12 

 inches scpiare, and closely connected by pickets or twig-hands, be 

 laid transversely on the bog, as shown in Plate XIII., figs, i, 5, 

 and 6; over these are to be placed longitudinal pieces of native 

 round timber of about 9 inches diameter, passing each other 2 or 

 3 feet at the ends; the number of these will depend on circum- 

 stances, but there should not be less than one under each rail; part 

 of the upper surfaces of these round timbers is to be adzed oft', to 

 make a level bed for the rough cross pieces of say 12X6 inches, 

 which are to be firmly spiked down upon them at a distance of 

 4. feet apart from centre to centre; longitudinal pieces of half 

 baulk are then to be placed on these to carry the rail; the space 

 may then be filled to the level of the bottom of the rails with 

 gravel and sand, better known in railway language, as ballasting 

 and boxing. If the longitudinal round timbers be immerous, cross 

 pieces of i-inch plank may be substituted for half baulk. 



It is proposed to adjust this road in lateral parallelism, as shown 

 in the anne.xed woodcut, by means of brackets c, bolted or spiked 

 on the cross timbers, and keys or wedges «, driven between these 

 brackets, and the longitudinal sleepers _/■, brackets at the centre 



and joints may be sufficient; 

 |(| the vertical adjustment to be 



made by wedges driven be- 

 tween the cross and upper 

 longitudinal pieces ; and 

 when subsidence takes place 

 to the extent of admitting 

 a filling piece, the wedges 

 may be taken out; the gauge 

 of the road to be preserved 

 from within by chocks, or 

 straining pieces between the 



i=^ 





longitudinal sleepers. It is to be observed, that the mode of 

 bracketing recommended, obviates all the difficulty of adjustment 

 which occui-s when the road pieces are fastened by bolts and 

 spikes. 



The object sought to be obtained by the method i)roposed, is in 

 the first place to include within the drains an extent sufficient to 

 give stability; and in the next instance, to ensure the permanency 

 of the state of drainage at which it may be thought advisable to 

 construct the framing, in order to attain by continuous bearing 

 tlie uniform resistance of the elastic material, of which the seat of 

 tlie road is composed. 



Fascines in Bug. 



If the bog be tolerably dry and not very deep, fascines, which 

 are not desirable, unless as a means of drainage, may he partly dis- 

 pensed with; in that case the round timbers may be laid on the 

 log; iu other cases, where a quagmire is to be got over, two or 



three layers of them may be necessary, placed in alternate longi- 

 tudinal and transverse layers, the transverse one being uppermost, 

 to receive the longitudinal round timbers. 



AV'hen fascines are used merely for drainage (Plate XIII., fig. 6), 

 for which jiuriiose they are particularly well adapted in bog, a 

 single continuous row of them should be laid with a proper fall in 

 the centre of the road uiuler the level of the round timbers; cross 

 rows leading from the side drains are to be made to communicate 

 with the centre, at distances of 15 yards apart, and by alternating 

 the cross rows at opjiosite sides, instead of making them meet each 

 other at the centre, a cross-drain will be had at every 7i yards in 

 length, and the portion of the drain not under the road may be 

 left open. 



The bavins or fascines used by Belidor in waterworks and in 

 military operations, were made of shoots of six or seven years 

 growth', from 7 to 1 1 feet long, and 30 inches round, well tied with 

 three bands, the first 1 foot from the head, the second 3 feet, and 

 the third G feet, so that tliere remained about 4 feet of brush- 

 wood or small ends not bound; such a form, although answering 

 the purposes intended — namely, for breakwaters or foundations, 

 would not make a continuous drain; neither does the contrivance 

 adopted by military engineers, called the "fascine choaker," give 

 any other than a circular form, and an insufficient and uneven 

 pressure, both equally uusuited to drainage; to obviate these de- 

 fects, we have had recourse to a contrivance shown in the annexed 

 woodcut, which gives a square 

 form, and the degree of com- 

 pactness required. 



Shoots of branches or brush- 

 wood of the requisite length 

 being procured, should be laid on 

 the moveable sole, on which cop- 

 per wires to serve as bands, are 

 to be placed transversely, in 

 number proportionate to the in- 

 tended length of the fascine, a 

 band in every 2 feet will be suf- 

 ficient; the faggot when put in, 

 should be 1 foot broad, and its 

 depth about three times what it 

 is intended to be compressed 

 to; thus 3 feet may be com- 

 pressed into 1 foot thick, and 

 i feet into say 18 inches. 



It will not be necessary to be 

 very particular in placing all 

 the shoots longitudinally, a suf- 

 ficient number, however, must 

 i-eceive that direction to give 

 continuity; the press will bring 

 all the rest into proper form, 

 which being done, the copper 

 wires are to be tightly drawn 

 I and twisted, and tlie ends of 

 I the fascines sawn evenly off, 

 so as to make a close butt- 

 I joint ; the press may be en- 

 ] larged to suit any length re- 

 quired ; fascines ought not to 

 I be less than feet hmg; the 

 cuttings of hedges, if held by 

 I a sufficient number of longi- 

 tiulinal branches, will form an 

 excellent bavin when pressed { ) 



in the manner described, which 

 is one of the great advantages of the machine. 



Canals in Bog, 



The process of canal making tin'ough bog is a subject demand- 

 ing especial consideration and inquiry; so much depends on local 

 circumstances that no rigid system of operations ap]dicable in all 

 cases can be specified — tlie jiosition of the bog, its depth, its con- 

 tiguity to recipients for drainage, the level of the substratum upon 

 which it rests in reference to the le\el of those recipients, the 

 level at which the canal is intended to enter the bog, the depth of 

 cutting to be removed, and the nature of the bog, whether firm or 

 flow, are considerations which must influence the course to be 

 adopted, as well in the choice of site, as in the method of perform- 

 ing the work, upon both of which the success of the undertaking 

 will depend. 



Smeaton, the aV.eit civil engineer of his day, having been coq- 



