74 



HARDWICKE'S SCIENCE-GOSSIP. 



existence of an underground ridge of Primary rocks 

 beneath the Tertiary and Cretaceous, or chalk strata 

 ol the southern and south-eastern counties. These 

 rocks are believed by geologists to occur in what are 

 termed by them anticlinal, or saddle-shaped arrange- 

 ment of strata. Like all other continuous ranges of 

 mountains, the tops of these subterranean hills 

 would be the first to be denuded and worn down, so 

 that the inferior strata would be touched by borings 

 that happened to strike their crests. It will be seen, 

 however, for the same reasons that farther away from 

 the strike or trend of this underground ridge the 

 rocks lying on the flank to the north and south 

 would be those of later geological date. This 

 means, in other words, that the farther south and 

 north we should go from the trend and the ridge, 

 the more likely we should be in borings to touch 

 rocks of Carboniferous age, or those which contain 

 coal. 



Many years ago, in a well-boring, close to 

 Harwich, the flanks of the buried Primary rocks 

 were reached at a depth of 1100 feet. The rock 

 fragments brought to the surface contained fossils 

 which demonstrated to the geologist that they were 

 those of the Lower Carboniferous period. This 

 lower division in England, at least, does not contain 

 coal, but an East Anglian geologist is led to infer, 

 by parity of reasoning, that a little further to the 

 north of Harwich, say somewhere in Mid-Suffolk, a 

 deep boring might possibly reach the upper rocks 

 reposing upon the flanks of this lower Carboniferous 

 series, which do actually contain coal. The dis- 

 covery of coal beneath the chalk at Dover is all the 

 more easy to be understood when we remember that 

 on the other side of the Straits the coal-fields of 

 Northern France are reached by borings through the 

 chalk at noo and 1032 feet respectively, and that 

 considerable quantities of coal are being obtained 

 therefrom. It will be seen that the situation in 

 which coal has been found beneath the chalk, 

 measuring in miles from the crest of the underlying 

 ridge in Hertfordshire and Middlesex south-easterly, 

 would be about the same distance measured north- 

 easterly, to some point in Mid-Suffolk. One of the 

 most remarkable things about these borings is the 

 comparatively low depth at which the Primary rocks 

 have been reached. If coal could be found in Suffolk, 

 say, at a depth of 1200 feet, that would scarcely 

 represent half the depth through which great shafts 

 are carried in rocks much harder and more difficult 

 to penetrate in the coal-fields of the north. 



The following statement has been made by Pro- 

 fessor Boyd Dawkins : " As the enterprise resulting 

 in the above discovery was begun and is now being 

 carried on under my advice, I write, after an ex- 

 amination of the specimens from the boring, to 

 ( Miirm the report of Mr. Brady. Coal measures 

 wiih good blazing coal have been struck at a depth 

 well within the practical mining limit, and the 



question is definitely answered which has vexed 

 geologists for more than thirty years. Further 

 explorations, however, will be necessary before the 

 thickness of the coal and the number of the seams 

 can be ascertained." 



The following is a detailed list of the strata passed 

 through in the boring for coal at Shakespeare's Cliff: 

 grey chalk, marl and gault, &c, to a depth of 

 560 feet, then Kimmeridge clay, &c, for a further 

 depth, of 600 feet, and lastly, coal measures, sand- 

 stones, shales, and clays for 20 feet. The seam of 

 good coal is 1160 feet below the surface, or 68 feet 

 lower than the point where the coal measures were 

 met with on the boring at Calais. The coalfields of 

 Northern France and Belgium extend across the 

 Channel, and they are at workable depth in the 

 southern counties. The Dover seam of coal is three 

 feet in thickness, and is said to be equal in quality to 

 the Derbyshire coal. 



NATURAL HISTORY NOTES FROM NEW- 

 ZEALAND. 



RN. HAWES writes (Kohimarama, Auckland, 

 • N.Z., Slh September, 18S9, received 15th 

 October) : — 



Here we are, and shall be for a long time to come, 

 in a transition state as regards the question of pre- 

 servation of native birds or plants. Quadrupeds we 

 have none, or next to none, though I occasionally 

 catch a black or native rat — one of those rats which 

 twenty years back were stated to be extinct. 



I do not know that many of the native birds can 

 be preserved, for I am sorry to say they seem to 

 disappear as the introduced birds increase, and as 

 the native plants and grasses get crowded out by the 

 invading host of those from all parts of the world, 

 good, bad, and indifferent, some brought here pur- 

 posely and others smuggled in, as it were, with 

 them, or in the straw and hay, &c, used for packing 

 purposes. 



With insects it has been the same, the large 

 cricket having been brought from India, it is said, in 

 the bedding of the troops sent from that country to 

 this in the war time, while the horrid mason wasp is 

 supposed to have come from Tasmania, in the holes 

 bored by other insects into the stringy bark rails sent 

 here so largely for fencing purposes a few years back. 

 If barbed wire had been invented by the ingenious 

 Yankee, and come into such general use here years 

 back as it has done now, we should not have im- 

 ported the rails, and our spiders (of certain species 

 that live and hunt among the grass and native 

 shrubs) would not have been in danger of extermina- 

 tion, with the at present unknown or unforeseen 

 accompanying results which are sure to follow. 



There is a boundless field now for some enter- 

 prising and painstaking Darwin or Lubbock to enter, 



