TllANSVCTIONS OF SECTION 0. 



881 



lifClai'lio's bt'autiful pvocivs.s, by tlic jipjtlication of (Iicnustrv, wiiIit, owiiio- its lianl- 

 i,.>sto tliivt coiunKin cause, cuiboiiatt' ofliiiit', is rciidrrLMl iis sol't ih the water Ironi 

 ■lif immntaiu liilvc. Taliiiijjp tliat oilier bnmcli of en^'iiieeriny coiniiionly cDiipled 

 with water, viz., the siipjily of pis, tlio en^jriiieer is helples.s without the apiilicaliou 

 ,.( flifiuistry. I'"roui the exaniiiiiiliim of tiie coal to \m useil, to the testing' of thu 

 _MS til lie •■'upplieil, tliero is not one ,sta<jre whore clu'mical science is not necessary. 

 The consumer requires ^ras whicli .shall be as nearly as possible a pure hydro- 

 carboa of hifrli illuminatinjif power, ami it rai^'hl well have been that a person to 

 whom was (lolivori!il the crude jias as it issued from the retort would have said, 

 'Certain thing's may bo separated out more or less, but. to practise on ,i whole- 

 siK' .scale tho delicate operations whicii will be needed to ch'anse the illunnnatini,' 

 as from its multifarious accom])anyiii^r im])urities is a hopeless uudertakin;,'-, 

 and must b(! so if for no other reason than this — the e.vco.ssivi^ cost that would t)e 

 tntftilfd.' But what are the facts? Althouffh 1 for one do not lilio to sit in a room 

 whi'Ve \:t\'^ is burnt, uidess special provision is made for takinir away the pnulucts 

 of combustion, the enjj^ineor of the present day, thanks to the application of 

 fheniical science, delivers gas to the consumer in a state of comparative ])urity 

 lalthouirii it may have been made from impuro coal) which but a few years ajjo 

 would have been deemed impo.ssible ; and so ftr is this impro\emeul from lieiiif^ 

 attended with extra cost, that the residual products not now uncommonly all but 

 pay the whole cost of the coal, and in .some rare instances even leave a .slight prolit 

 tijL'o towards the charge lor labour. Again, it is by the ajiplication of chemical 

 science in the dynamite and the gun-cotton of the present day that tho engin(H'r is 

 ^nablfd to prepare submarine foundations, to blast away shoals, and t<i drive tunnels 

 tbniL'li rock of a character that cannot be dealt with by mere cutting-machines. 

 I/liially to tho application of ciieuiistry is it due that there are hopes, by tho em- 

 ployment of lime cart ridges, of breaking down coal without that risk oi' ii'niling tire- 

 ilamp wiiich is atteiulant upon the usf of gunpowder. I need hardly observe tluit 

 miieh more might most pertinently ))e said on the Avay in which the engineer 

 api)lie.s chemical science. In fi '^t, those ways are so multifarious, that a volume 

 !iii;.'ht be writtt'U upon them, out I nui-il ])ass on and ask you to cmisider how tlio 

 rwiiieer applies gtH)logical science, the science treated by Section 0. 



I have already spoken of the engineer supplying towns by water collected from 

 the surface ; even he, however, must have a knowledge of geology, for without it 

 lie will not know what places are apt for the huge reservoirs lie constructs, nor 

 Inhere he can in safety make his enormous embankments. In this continent of 

 vast lakes one feels it must excite a .sensation of the ridiculous when a ' Welsh lake ' 

 isspoken of, but I must ask you to believe you are in Lilliput, and to imagine tiiat 

 ilie 'Bala Pond' of eleven hundred acres in extent is really 'Bala Lake,' as it is 

 called. Within a few miles of that, our friends at the other end of tho Atlantic 

 torn ferry, the inhabitants of Liverpool, are now constructing, under the engineer- 

 b,' and advice of Mr. Hawk.«ley, waterworks which will involve the formation, 

 I ljeliev(> one may safely say the re-formation, of a lake, practically the same area as 

 that of Bala, of some 80 feet in depth, and containing between tho overtlow and 

 tlie noint of lowest discharge nearly twelve thousand million gallons. This lake 

 'ill De made by the throwing from side to side of the valley of a solid stone bank, 

 loo feet above the ground, 14(3 feet above the deepest part of the foundations, and 

 li'j feet thick at its thickest part. Contrasted with Lake Superior this new 

 ike will be small, a thing even demanding a microscope, but the bursting 

 ; the wall would liberate a body of water sulHcient to carry death and ruin 

 ■^ronL'liout a considerable district. It is, therefore, in the highest degree im- 

 pTtant that whether he bo constructing the solid stone wall, or the more 

 wmmon earthen embankment with a puddle trench, the engineer should so 

 ipply geological science as to ensure the safety of his work. But in those 

 casts where the waterworks engineer has to derive the supply from under- 

 nound sources, the application of this .science is still more nece.s.sary ; he must 

 how whether he is likely to iind a water-bearing stratum at all — if so, ^vhero 

 it receives the rain from heaven, and the extent of the area which receives it ; in 

 «iiat direction the water travels through it, what is the varying height of water 



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