KNOWLEDGE 



since, that it requires the most careful study even to 

 detect the almost obliterated traces of these grand move- 

 ments. 



The Alps and the Himalayas during their elevation 

 have suffered enormous waste and denudation ; but if the 

 elevation were to cease and the waste to go on tiU these 

 magnificent mountain chains were reduced to masses of 

 diminutive peaks, ranging from 2,000 ft. to 8,000 ft. in 

 height, we should then have the counterpart of this 

 stupendous ruin of the mountain chain of the north. 



The history of the series of successive movements to 

 which the rock masses of our Highlands has been sub- 

 jected is one well worthy of the most attentive study. 

 When the evidence bearing upon the subject is carefully 

 sifted and weighed we become convinced of the fact 

 that many of these movements — including some on a 

 prodigious scale— must have taken place during what 

 we are commnTilj tvccustomed to regard as compara- 

 tively recent geological periods. On the eastern coast of 

 Sutherland a mass of secondary rocks, including several 

 thousands of feet of triassic, rhtetic, and Jurassic strata, 

 have been let down by a gigantic fault, so as to be placed 

 in jujstaposition with the old red sandstone and the crys- 

 talline rocks. Now, taking the very lowest estimates of 

 the thicknesses of the several strata affected, the vertical 

 "throw" of this fault must have exceeded a mile. It 

 may not improbably, indeed, have been at least double 

 or treble that amount. Yet this great dislocation was 

 certainly produced at a later date than the upper Jurassic 

 period, for rocks of that age are found to be affected 

 by it. 



Along the coasts of the Black Isle strata of middle and 

 upper Jurassic age are similarly found faulted against 

 the " old red " and the crystalline rocks. On the other 

 side of the North Sea, in Ando, one of the Lofoden Isles, 

 a patch of lower oolite strata, consisting of marine and 

 estuarine strata, and including beds of coal like that of 

 Brora, is found let down by gigantic faults into the 

 very heart of the crystalline rocks of the district. In 

 Scania the whole of the secondary rock masses owe their 

 preservation in the same way to a plexus of tremendous 

 faults, by which they have been entangled among the 

 harder rocks. Those faults have affected not only the 

 Jurassic strata, but even the very youngest members of 

 the cretaceous series. 



Nor are we without evidence that some of the great 

 faults are of post-cretaceous age in this country, for 

 in the Western Highlands displacements of several 

 thousands of feet have been detected which affect not 

 only the upper cretaceous, but also the older Tertiary 

 rocks. 



The effects produced by these great dislocations, which 

 had a generally parallel direction in onr Highlands from 

 north-east to south-west, are of the most startling 

 character. Great strips of triassic and old red sandstone 

 strata, like those of Elgin and Turriff and Tomintoul, 

 and of the line of the Caledonian Canal, are found let 

 down among the crystalline rocks by these gigantic 

 faults. The great central valley of Scotland itself con- 

 sists of masses of newer Pateozoic strata, faulted down 

 between the harder Arch^an and lower Paleozoic rocks, 

 which form the Highlands on the one hand, and the 

 border land on the other. That many of the stupendous 

 earth movements which produced the foliation of the 

 rocks of Scandinavia and the Scottish Highlands must 

 be referred to Archisan times there is not the smallest 

 room for doubt. That similar effects have resalted from 

 the same agencies during subsequent periods our fellow 

 geologists in Scandinavia believe they have found incon- 



trovertible proof. For my own part, I look forward 

 confidently to the establishment of the same conclusion 

 from the study of our own Highland rocks. 



E^ 



THE YOUNG ELECTRICIAN. 

 By W. Slingo. 

 (Continued from p. 199.) 

 X. CVIII. Fig. 61 illustrates a form of electroscoi u 



hich may be very easily and cheaply made, 

 glass shade may consist of any ordinary bottomless un- 

 stoppered gas jar having a diameter of three or more 

 inches, and a height of six inches or thereabouts. Jars 

 of this kind are, comparatively speaking, dear, but the 

 expenditure is not at all necessary, more especially if it 

 is preferred to put one's self to a little trouble in order 

 to save expense. The jar may be readily obtained by 

 cutting down an ordinary clear glass bottle, such a one 

 as spirits, iSrc, are often sold in. Tlie cutting presents 

 no serious difficulty if a little care is taken. Suppose 

 A B, Fig. 62, to be the bottle. The neck usually bulges 

 a little, as at C D. This is perhaps an advantage, for if 

 the neck is a long one, we can cut it at C D, and the 

 conical neck resulting will assist in fixing the stopper. 

 Tie CIS tiffhfhj as 2wssibJe pieces of fine twine round the 

 neck at C D, and round the bottom of the bottle at E F. Then 

 revolve the bottle in the flame of a spirit lamp so as to char 

 in turn each piece of twine without setting fire to it. It 

 will be found possible, after a few revolutions, to divide 

 the glass by tolerable clear cuts under the twine, a gentle 

 tap being applied now and then as the heating progresses. 



A similar process, answering as well if not better, is to 

 soak a piece of knitting-cotton or worsted in paraffin oil, 

 tie it somewhat tightly to the bottle and then set fire 

 to it. The bottle should be held horizontally, and pro- 

 tected from any considerable draught, so as to confine the 

 flame as nearly as possible to the line of the cotton. After 

 allowing the oil to burn nearly out, plunge the bottle in 

 a basin of cold water as far as the cotton, when the 

 neck or bottom, as the case may be, will fall off, leaving 

 a tolerably clean cut. 



These are plans which I have rarely found to fail, and 

 have used them on several kinds of glass. Crosse & 

 Blackwell's wide-mouthed pickle-bottles answer famously, 

 and would be recommended for this purpose, were it not 

 that the glass is somewhat too green. If the cut edges 

 of the glass are exceptionally rough or uneven they 

 may be filed down with a smooth or second-cut file, 

 applying the tool gently. If a bastard (or coarse) file is 

 used, or if too much pressure is applied, there is great 

 danger of chipping off more than is desired. When 

 tolerably even, the edges may be made as smooth as 

 desired by grinding down on medium emery-cloth 

 moistened with turpentine. 



The jar being made, the next step is to fit the stoppei" 

 (D Fig. 61). This may be an indiambber cork (this is 

 suggestive of an " iron milestone," by the way) or stopper. 

 Such an article answers admirably, but it is expensive. 

 Let us use either a good sound cork or, equallj- well if 

 not better, a piece of dry wood — mahogany will do 

 nicely. If there is any doubt about its dryness, place in 

 a warm oven for a short time. Then cut it to shape and 

 bore a hole through the centre (longitudinally) a quarter 

 of an inch in diameter. Next immerse it in melted 

 paraffin wax, until it is as thoroughly saturated as pos- 

 sible : this will prevent the subsequent entrance of 

 moisture. Leaving this to soak, let us next cut off two 



