1842.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



273 



exlnusleil parts reduces the ]io«cr required to wcrk the air-pump to a smaller 

 proportion of power exerted by tlie engine than formerly. And in particular 

 the valves and «ater-wavs through tlie pumps are made more open than for- 

 merly, so as to diminish the lo?sof force that is occasioned by resistance of the 

 water; that lossof force by resistance increases as the square of the velocity of 

 the motion, when loss of force by mere friction does not increase by increase of 

 that velocity. He believed few'larse engines in Cornivall, which are making 

 what is now' thought tolerably good performance, lose more than at the rate 

 of 3 lbs. per square inch of the piston, by friction of their moving parts, and 

 by resistance of the water, and by working their air-pumps, and the best 

 and newest engines probably still less. It would of course be understood 

 that he meant by ."! lbs. what is commonly called li lb. fur moving the en- 

 gine each way. or through each half stroke ; but that is not a correct way of 

 statingit; IJ lb. friction incoming in-doors.and 1= lb. friction and resistance 

 of water in going out-of-doors, would be more likely to be correct. AVith 

 all that has been done in Cornwall, these matters still admit of further 

 improvement. 



BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE. 

 Twelfth Meeting, 1842. 



[We are indebted for the following report partly to our ovrn correspond- 

 ents, and partly to the Athenceum and the Manchester Guardian — the latter 

 paper gave a verv- copious account of the whole of the proceedings, includ- 

 ing the speeches delivered at the dinner.] 



Report from the Committee on R.iiLv.w Sections, presented by 

 Professor Vignoles. 



A grant of 200/. from this Association was made at the Glasgow meeting 

 in 1S40, on a joint application from the Geological and the Mechanical 

 Sections, towards obtaining profiles of the various railways, chiefly with a 

 view of putting on record (before tlie slopes of the excavations become 

 soiled over and covered with vegetation) the geological appearances and 

 strata developed in the many vast openings made through the country by 

 the operations of modern engineering. At the Devonport meeting last year 

 a renewal of the unappropriated balance of the first grant was made ; the 

 whole sum has since been expended, and the results are now laid before the 

 Sections originating the subject, in the shape of the numerous working plans 

 and sections of several cf the railways, and of the enlarged parts of the 

 profiles of the excavations. 



In obtaining these the Committee appointed by the Association have great 

 pleasure in reporting, that they have been aided in the most effective and satis- 

 factory manner by all the railway companies to whom they have applied, and 

 also by their several officers, the engineers in particular having taken extreme 

 pains and great interest in forwarding the views of the Association. M'ben 

 so many parties have thus zealously co-operated, it might be almost invidious 

 to name one without specifying all; but in particularly mentioning Mr. 

 Swanwick, the engineer of the North Midland Railway, the Committee wish 

 to do so for tl-.e purpose of remarking on the great pains taken by that 

 gentleman in marking, as his works went on, all the geological details of the 

 cuttings, which pass through so interejfing a region, and which has put into 

 the possession of the Committee a vast extent of most valuable records of 

 the kind sought for, and which at the same time forms a most striking 

 example, well worthy of imitation, of the combination of engineering and 

 geological information, applicable for economic purposes. 



The Committee were not at first able to organise a system of working the 

 grant to their entire satisfaction ; but they found after some experience that, 

 ■with the favourable disposition shown by all the railway companies, they 

 might (without increasing the e.-:pense,) by degrees and in nn great time, 

 be able to form an interesting and valuable collection, not only of the sec- 

 tions of the excavations of the railways, but of the whole of the plans and 

 profiles of all the lines, which, concentrated in one public depository, and 

 open to the inspection of all scientific and literary bodies and individuals, 

 and to the public in general, under proper regulations, would be of high 

 interest. In fact such documents were almost necessarily required, as the 

 mere indices whereby to identify the particular geological profiles ; and so 

 useful and important is such a collection likely to become, that it is not 

 unreasonable for the Committee to hope and believe, that after another year's 

 experience shall have matured their arrangements and perfected their pro- 

 posed system of records, and brought down the expense to a .certain and 

 moderate rate per mile, the subject maybe taken up by Her Majesty's 

 Government, and made to form part of the great geological survey of the 

 United Kingdom, conducted by .Sir Henry De la Beche, in connection with 

 the trigonometrical survey now carrying on by Colonel Colley and the offi- 

 cers of the corps of Royal Engineers. The Committee, therefore, are nut 

 without hopes that the geological and mechanic .1 Sections will again unite 

 in applying to the General Committee for a further grant cf 200/. at the 



present meeting, to enable them to complete the organization they have 

 began. 



The documents which the Committee have to submit are the following:— 



1st. Plans and sections of the whole of the Midland Counties Railway 

 from Rugby to Derby and Nottingham, about 58 miles. Knlarged sections 

 of the cuttings on that railway, prepared to be filled in geologically. The 

 chief characteristics of this district are the gv'psum beds, commonly called 

 plaster of Paris, and the hydraulic lime, well known to engineers as the 

 Barrow lime. 



2nd. Plans and sections of the whole of the North Midland Railway, 

 from Derby to Leeds, about 72 miles. The entire of the geological details 

 have been laid down on the working sections of the cuttings ; but as it has 

 been considered by the Committee that a uniform system should be observed- 

 enlarged sections have been prepared, on which, as on the similar sections of 

 the other hues, the strata should be delineated. It may be observed here, 

 that these enlarged sections are on the natural scale of 40 ft. to an inch. 

 that is, the vertical and horizontal scale are alike, which is not always the 

 case in ordinary geological sections, and very seldom so with the working 

 sections, for earth work and similar engineering purposes. This railway 

 intersects the coal districts for many miles, and is replete with interesting 

 objects. 



3rd. Plans and sections of the Manchester and Leeds Railway, from Man- 

 chester to Normanton. about .30 miles. These latter are not quite finished, 

 but will be so before the close of this meeting. Enlarged sections of a con- 

 siderable portion of the excavations on this railway, are filled up with the 

 geological details. 



4th. Enlarged sections of the excavations on the Glasgow, Paisley, and 

 Greenock Railway, about 22i miles, with the geological details. 



5th. The same for the Manchester and Bolton Railway, about 10 miles, 

 containing full details of the strata where the remarkable fossil trees were 

 found, and of the trees also, models of which are in the exhibition room at 

 the Royal Institution in Manchester. The liberality of this company will 

 afl'ord several opportunities for the members of the Asscciation to visit these 

 trees, and the particular profile of the excavation where they are will remain 

 in the Geological Section, or in the Royal Institution, where the models are. 



6th. Enlarged sections of the Hull and Selby Railway, about 30^ miles, 

 with the geological details. 



Some other enlarged sections are stated to be preparing for the Committee, 

 but they have not come to hand in time for the present report. 



These records, according to the directions of the Association, will be de- 

 posited in the Museum of Economic Geology, in London, where they may at 

 all times hereafter be usefully referred to. 



In conclusion the Committee cannot refrain from observing that the docu- 

 ments thus collected are equally important and interesting to the philosopher, 

 the geologist, and the engineer. To the philosophical or theoretical investi- 

 gator they present the curious and varying features of the crust of this 

 portion of the globe ; to the practical engineer they offer a memorial of the 

 experience of the profession, whence many a serviceable lesson for future 

 operations maybe learned ; whereby difficulties and expense may be hereafter 

 avoided and diminished, and from which valuable information may be derived 

 for tlie appliance of materials in constructions, it being one of the great arts 

 of the engineer to avail himself of the most, immediate natural resources 

 which he has to displace in one instance, and to apply them usefully in 

 another, when in juxta-position. And, on the other hand, the minute vari- 

 ations of strata and soil thus accurately delineated, and referred to well- 

 defined altitudes, with respect to the general surface of the ocean, become of 

 the very highest interest to the geologist, and no less so to the mining 

 engineer, more especially on the lines of railway intersecting the coal and 

 mineral districts, where, in numerous instances, labour, directed by science 

 and sustained by commercial enterprise, has laid bare in deep chasms the 

 secrets of Nature, and the stores whence this country has derived so many 

 advantages, and whose well-directed energies have drawn from our mines 

 of coal and rude metals that abundant wealthland prosperity which the more 

 splendid productions of Potosi and Mexico have failed to bestow on their 

 possessors. 



On Straight Axles for Locomotives, by Prof. Vignoles. 



The fatal results of the late terrible catastrophe cii the Paris and Versailles 

 Railway (rive gauchej has draw n the attention of the public in general and 

 engineers in particular, to the causes which produce such fearful elVects ; and 

 the breaking of the axle having been prominently put forward as the original 

 occasion of this and many other railway accidents, it seems desirable that a 

 dispassionate in(iuiry should be instituted, and an endeavour made by calm 

 discussion to elucidate truth. 



It is not intended, in the present note, to allude, cwept in general terms 

 to the above accident. It is clear that the breaking of the axles in this case 

 was not of itself sufficient to produce such a disaster. It was not the driving 

 axle that broke, but the fore axle of the small four-wheeled engine; and it 



