1844. 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



361 



nel, for the insertion of the crown bars, and is then widened out to the right 

 and left, and the bars inserted one by one down to the level of the top sill, 

 It will be remembered, that the crown bars for the leading lengths were de- 

 scribed as left above the brickwork of the side length, to be drawn out (of 

 their cells) to form the roof of the leading work, length after length ; by 

 which means, the same bars travel along the roof to the next junction, unless 

 by accident any of them get bj-oken, or stick fast in some part of their jour- 

 ney ; whereupon they are generally built in, and left. It is, however, not 

 the safest of practice to draw the crown bars from the side lengths at all, but 

 to build them in, and leave them, unless the ground is very good, when their 



as to cause snch an effect, it would probably be unwise to draw the bars at 

 all, were it even possible to do so, lest a movement be given to the earth that 

 would be liable to [produce results far more costly tlian the value of a few 

 bars. 



When the bars are drawn, great care should be taken, as before stated, 

 that the space from whence they are removed is packed and rammed solid 

 with earth ; for the danger of leaving an empty space above the arch is too 

 obvious to need any remarks. It is also of importance that attention be paid 

 to the amount of sinking that takes place in the top of eacli length whilst 

 standing in timber, in order that the leading ends of the bars for the suc- 

 ceeding lengths may be raised sufficiently high above their required level to 

 allow for their sinking, before the arch is turned. 



Our readers will see by this rather lengthened extract the very- 

 business-like manner with which our author proceeds with his work. 

 Mr. Simms next gives some particulars of the actual cost of labour, 

 calculated from the number of men employed and checked by the con- 

 tract price paid for the work, by which it appears that the cost of ex- 

 cavating the leading lengths of the Blcchingley tunnel, each 4 yards, 

 was £42 17s.; this amount includes £3 for powder and candles and 

 £1 5s. for tools, &c. The average price to the contractors (gangsmen) 

 was about £11 per lineal yard, and for the Saltwood tunnel, each 

 length of 4 yards, the estimated cost of the excavating was £28, or 

 £7 per lineal yard. 



The 13th chapter is devoted to the tunnel entrances, the shaft towers, 

 and other finishing works. The 14th explains the construction of 

 centres, and of Frazer's patent centres ; and the 15th contains some 

 useful information connected with tunnelling. 



We have thus gone through this practical work, and before we con- 

 clude we must observe, that besides the numerous wood engravings 

 with which it is illustrated, there are IJ copper-plate engravino-s by 

 Lowry, accurately delineating the progress of tlie works in the° con- 

 struction of the tunnel. To Engineers generally do we recommend 

 this volume most strongly ; and to alt Resident Engineers do we say 

 " Go, and do thou likewise." 



The Metropolitan Buildings Act. 7^8 Vict. c. 84. tFith Notes 

 and Cases. By George Tattersall, Surveyor, and Messrs. Cham- 

 bers, Barristers-at-Law. London : Lumley. 



The New Buildings Act will of course be in the hands of every 

 professional man, and, in order to afford a convenient and comprehen- 

 sive manual, the authors of the book before us have republished the 

 act, with the necessary notes, an abstr:ict and analysis of the act, a 

 glossary of the terms employed, and a list of district surveyors. We 

 notice, however, one very great defect in a work of this nature, the 

 want of an index. 



removal would be attended with perfect safety. They were mostly left in a. 

 Blcchingley ; as their value was of trifling importance, compared with any 

 risk to the security of the work that carried the shafts, through disturbing 

 the earth thereabouts ; for, although the space from whence each bai is 

 drawn is, professedly, rammed solid with earth, by a man standing at the 

 end where it is drawn, using a long-handled punner, — yet, however well and 

 carefully this may be done, it would, in most cases, be better that the bars 

 were built in, than that the surrounding earth should be in any degree dis- 

 turbed : and, too often, if the men are not watched, they will omit the ram- 

 ming altogether, as their neglect cannot be detected afterwards. 



The annexed engraving represents the process of 

 drawing the crown bars, whether from over the 

 side or any subsequent leading length. The top 

 heading is shown as having been already driven, 

 and one bar a drawn forwards, and its advanced 

 end resting upon the shelf of earth ii, preparatory 

 to its being propped ; the ground is also shown as 

 ready for another bar, c, which the men arc draw- 

 ing from over the brickwork of the last turned 

 length, D ; the leading centre rib, _e, is shown in 

 section under the brickwork, also an end view f, of 

 the top sill, and the upper end of its raking prop g. 

 The drawing of the birs can mostly be accom- 

 plished with crow bars, used as levers, as shown in 

 the annexed engraving, which brings them forward 

 by little and little, till the larger portion of them 

 is advanced, and then they come out easily enough ; 

 but if, during their confinement above the brick- 

 work, any particular settlement has taken place, 

 the bars will frequently be jammed in extremely 

 tight ; the only way then to release them is by the 

 use of one or more screw jacks placed horizontally 

 against the arch, and lashing chains passed over 

 these and also round the projecting ends of the 

 bars, when upon working the screws, the bars are 

 released. If however, the resistance is to great to 

 be overcome in this manner, the bars are left and 

 built in ; for where a settlement has been so great 



Ansted's Geology. Vols. 1 and 2. London : Van Voorst. 



We have received this work, completed in two volumes, but we 

 feel we could not do justice to it were we to attempt this month to go 

 through it. The first number gave us too favourable an impression of 

 the work to allow us to pass it cursorily by. 



Illustrations of Baptismal Fonts. London : Van Voorst. 



This valuable work is now completed, and as we are anxious to con- 

 sider the introductory essay, we shall postpone until next month the 

 remarks which we are desirous to make with regard to it. 



EPITAPH ON A DECEASED ACADEMICIAN. 

 A Porlrail. 

 Here lies of men the most malignant ; 

 The very earth feels quite indignant. 

 At covering such a shrivelled mass 

 Of envy, malice, spite and brass : 

 He envied rank, he bated beauty. 

 And spat at genius as a duty ; 

 And when be tottered to his midnight bed. 

 He lifted up his trembling hands and said- 

 Ob Go<l ! 1 thank tliee, that once more 

 I've passed another day, as spitish as before ; 

 Grant me but life to see to. morrow! 

 How I will mortify disease and sorrow. 

 How I will slime my species with my spittle, 

 To show mankind I hati> them— 'cause I'm little. 

 The morning broke in innocence and light, 

 He ope'd his eyes with their accustomed spite 

 And chuckled at the tbuught of all he'd wound ere night. 

 In vain ! Death sejzed him with a hurrjeil grasp. 

 For e'en Death feared the withered asp. 



B. R. H.WDON. 

 September, 1844. 



