3IO 



NATURE 



{Feb. i8, 1875 



entrapped in the growing solid, and the gas not having 

 time entirely to make its escape. In the case of many of 

 these open cracks it would seem that the freezing took 

 place so rapidly when it once began, that the air could 

 not be all expelled, but the air-bubbles were lengthened 

 out in their endeavour to set themselves free, and preserved 

 in the form of very delicate tubes, pointing from the 

 crack walls on either side slightly downwards and towards 

 the centre, where solidification would last take place 

 (Fig. 5). Along the central line of the crack occurred 

 another series of perpendicular tubes caused by the 

 elongation of the bubbles in the only direction then 



possible to them. Nothing could exceed the beautiful 

 regularity of structure thus caused. In a few instances 

 there was a double series of such an appearance as is 

 represented in Fig. 5, the crack having again opened, 

 apparently, along the same line, and a similar structure 

 to the former having been produced. In this connection 

 it is interesting to note the seeiyiingly frequent evidence 

 of fracture recurring along the same lines, especially if the 

 explanation given above of the vertically-veined cracks 

 be the correct one. 



The drawn-out air-bubbles were also particularly beau- 

 tiful around the stones and rocks in the shallow water 

 at the edge of Derwcntwater. Much of the very 

 smooth ice which covered the lake on the morning of 

 Wednesday, the 23rd of December, had been formed 

 under a very sharp and sudden frost, the thermometer 

 in a sheltered position registering 1 8^ of frost. The ice 

 would first form around the stones in shallow water, and 

 form more cjuickly there than out in the open, where 

 there were no marked centres of crystallisation ; hence 

 the number of bubbles entrapped were greatest around 

 the stones and rocks close to the surface, at the lake-edge ; 



Fig. 4. 



and the bubbles, trying to escape downwards as soon as 

 the upper layer of ice was formed, became beautifully 

 drawn out and fringed the stone most delicately. I have 

 occasionally observed a somewhat similar lengthening of 

 gas or liquid cavities when examining thin slices 

 of such rocks under the microscope as have under- 

 gone solidification under tension in one given 

 direction. 



Before closing these few remarks, allusion may 

 be made to two other effects noticed during the 

 late frost. One of these is the precise [analogy 

 between the deposits of ice often formed on a rocky 

 slope, or by constant dripping from above, and the 

 deposits of carbonate of lime formed in caverns. The 

 trickle of a thin stream of water over a rocky slope, 

 such as may be seen in many parts of the Clapham 



Fig. 5. 



Cave, deposits a wrinkled wavy layer of carbonate 

 of lime, and over it the water seems ever to keep 

 up a rhythmic flow. Upon rocks near the summit of 

 Honister Pass I noticed during the late frost an icy sheet 

 precisely similar, and with the same pulsating streamlet 

 flowing over, while, hard by, there were sheets of icy 

 stalactite and stalagmite only to be distinguished from 

 those of limestone caverns by their greater clearness. 



Another feature of great beauty was the effect of the 

 bright sunshine on the icy crystals scattered broadcast over 

 the snow of Skiddaw. Looking slightly away from the 

 sun at a certain angle, and inclining one's head so as to 

 look along the ground, there appeared scattered in bound- 

 less profusion thousands of brightly coloured gems, blue 

 and green being the most marked colours, but many a 

 ruby lying interspersed with these mountain emeralds. 

 Assuredly Skiddaw top never showed to greater advan- 

 tage than during those cloudless wintry days of the 

 Christmas and following week ; and it seems a marvel- 

 lous pity that of the thousands who visit this favoured 

 spot during the hot days of summer or the wet ones of 

 autumn, so few should ever return to see their majestic 

 friends 



"Clothed in white s.^mite, mystic, wonderful." 



It may interest some to learn that something analogous 

 to a Swiss glacier was once observed among our Cum- 

 berland mountains. Beneath the summit of Dale Head, 

 2,500 feet high, is an old copper mine, and many years 

 since two miners entered the old workings in the month 

 of June to obtain some mineralogical specimens. Great 

 was their surprise to find the level, but a short way in, 

 full of snow and ice. The mountain-slope is there very 

 steep, but with many a hollow and rugged fissure in 

 which the snow lies long, and doubtless it had found its 

 way from above into the old level, as well as having been 

 blown in at the mouth. The trickhng of tiny streams 

 among this snow, and the alternations of frost and thaw 

 so frequent upon the mountain sides, must have produced 

 an icy mass, which would be long ere it melted, and thus 

 a natural ice-house was well supplied with ice far into the 

 summer. The winter previous had, I believe, been a very 

 snowy one, and it is not likely that the phenomenon is 

 of very frequent recurrence. 



J. Clifton Ward 



SCIENCE AT BANBURY 



AT the opening of a new Literary and Philosophical 

 Society at Banbury the other day, Mr. B. Samuel- 

 son, M.P., gave an inaugural address in which he touched 

 on various topics connected with the progress of science 

 and scientific culture. We regret that our space prevents 

 us from giving Mr. Samuelson's address at length ; the 

 following extracts, however, we believe, will interest our 

 readers : — 



" There have, doubtless, been times when the pursuit 

 of learning was carried on with as much ardour, when as 

 great sacrifices were made for the discovery of truth, or 

 when there was at least an equal toleration for differences 

 of opinion, as in our generation ; but I think it may safely 

 be asserted that at no period since the revival of letters in 

 the fifteenth and sixteenth centuries have these conditions, 

 essential as they are to the success of our objects, co- 

 existed to the same extent as in our day. It may not be 

 one of the least useful and interesting subjects of inquiry 

 for our society how this favourable conjuncture has arisen. 

 Probably it will be found to be one, and if so, certainly 

 not one of the least important, of the results of the great 

 material changes which have their origin in the substitu- 

 tion — begun in the age of Watt, and still in course of 

 development — of machinery for manual labour. At any 

 rate we may congratulate ourselves that the experience of 

 the present age proves the dogma to be fallacious which 



