HARDWICKE'S SCIENCE-GOSSIP, 



227 



perched boulders pitched up by the winter ice block ; 

 and we were now at noon monotonously reeling uji 

 cargo in the water-way at Selsovig with a rock 

 sculptured like a cathedral porch adown the vista, 

 whose remoteness in the singularly deceptive Arctic 

 air it would be hazardous to estimate. We lay just 

 on the edge of that crown of light, the Arctic circle, 

 and the sun shot a searching ray as from a burning 

 glass, rendering it uncomfortable to bask with the 

 bluebottles, so I went below and turned up a 

 Norwegian paper on the saloon cushions, and perused 

 an article composed by some Anchytas, who had dis- 

 covered that this cap had once sat awry. After 

 alluding to Professor Gylden's researches at Poltava 

 it ran briefly as follows : — If we suppose the forces in 

 operation to have acted unchanged, in 600 years the 

 North Pole would have shifted the tenth of a minute, 

 and after 360,000 years a degree ; and in order that 

 it should shift 10 and 20 degrees of latitude, we must 

 look back 3,600,000 years and 7,200,000 years. This 

 displacement would be required, before the Arctic 

 land now buried in snow and ice could produce a 

 tropical or sub-tropical vegetation like Spitsbergen 

 in the miocene age ; when it was so warm as to be 

 clothed with woods of lime, magnolia, plane, oak, 

 hazel, poplar, swamp Cyprus, and sequoia. For- 

 merly people supposed that the Arctic circle was 

 immovable, but then no locality for tertiary fossil 

 plants in Northern Asia was known, save Kamskatka. 

 However, when Professor Heer came to describe 

 those of Alaska collected by Bergmeister H. Furn- 

 hielm, which now compose a portion of the Royal 

 Museum collection, he remarked that these must 

 have grown in a climate less warm than the rest of 

 the tertiary flora in the same degree of latitude, and 

 in a still greater degree did this supposition become 

 evident when he examined the fossil plants from the 

 island of Sachlin, whence he drew a conclusion that 

 the isotherms dipped then lower in the East of Asia 

 than in Europe. The matter was further confirmed 

 when Nordenskjald discovered at I^Iogi, in the south 

 of Japan, plants that similarly bespoke a colder 

 climate. All this is perfectly accounted for by con- 

 ceiving the pole to be displaced the aforesaid 20 

 degrees, and thus to have lain in 70 degrees north 

 latitude, and 120 degrees east of Greenwich, jvvhen 

 the flora of Japan would be brought between the 53rd 

 and 55th parallels, and Greenland to the 53rd. 

 Oeningen, which boasts so many fossil palms, would 

 then have been in the 36th degree of north latitude, 

 and would have possessed the climate of Algeria. 

 Allowing this, it is manifest that in the glacial age 

 and time of the hairy mammoths, the pole must have 

 left its position in Eastern Siberia, and shifted over to 

 Northern Europe. 



The moths fly to light, the wheehng swallows at 

 the approach of the northern chill swoop after the 

 sinking sun, and the shy fieldfare and plump missel 

 thrushes, bewildered at the loss of their endless day, 



wander in search of it along our hedgerows ; but in 

 this country of oe and cy\ I miss the sound of the 

 children's voices in their play, that Norse-Asturian- 

 Gothic warble of sunny notes that, even more than 

 the Italian, seem framed to charm. 



A SUCCESSFUL DAY'S GEOLOGISING. 



THE latter end of last summer, a friend and 

 myself resolved to spend a Saturday in ex- 

 amining some good examples of the upper chalk — or 

 Senonian, as it is termed by Geikie — in the lower 

 portion of the Medway valley, near Chatham. 



By good fortune we met in a pit at a village close 

 by called Luton, a gentleman who has had great 

 experience with the geological features of this part of 

 the county of Kent, and with his assistance we 

 obtained a tremendous number of fossils, etc. He 

 has also kindly furnished me with an account of the 

 strata in the locality, notes from which, together 

 with a short description of the "treasures" we 

 obtained, may induce other amateur geologists to 

 make an excursion to this interesting part of Kent. 



The most prominent features of this district, the 

 remains of an old plain of marine denudation, are the 

 grand escarpments ; the first overlooking the lower 

 London Tertiaries around Upnor, reaching from the 

 Chatham "Lines" to Bredhurst, a distance of about 

 three miles in a south-easterly direction, and the 

 other and steeper one at Blue Bell Hill, and north of 

 Boxley, overlooking the Weald of Kent, from which 

 the finest view in that county is obtained. 



The upper chalk thus exposed, taken as a whole, is 

 rather thick ; at Snodland, lower down the Medway, 

 310 of the 600 feet of chalk belongs to the Senonian ; 

 at Wouldham, six miles above Chatham, it only 

 occupies 12 of the 544 feet of cretaceous rocks; at 

 Cuxton, further down, 120 feet ; at the Great 

 "Lines," 300 feet; at Blue Bell Hill, 380 feet; at 

 Fort Borstal, 230 feet ; and at Fort Clarence, 154 

 feet. 



There are numerous fine sections of this formation 

 along the two great escarpments, as well as very fair 

 ones of the London Tertiaries. One at Luton shows 

 that peculiar kind of excavation, or pothole, caused by 

 the unequal wearing of the chalk, or by roots of trees, 

 and known as a "pipe" (Fig. 135). Many other 

 sections show these pipes, and all are filled with 

 debris from the strata above the chalk, principally 

 Thanet sands and gravel ; while in one, Mr. Gamble, 

 the gentleman we met at Luton, has found a very 

 much worn tooth of Elephas primigcnius, many 

 remains of which have been obtained in the gravel in 

 the valley, and in the river itself. 



In many places the chalk has been greatly dis- 

 turbed. Mr. Gamble states that Wouldham Common 

 seems to have slipped over the underlying clay ; this 

 could only have occurred after the river had exca- 

 vated its present valley. Further proofs of disturb- 



