.34 



NATURE 



[May 9, 1872 



here the physiography of the district was pointed out. After 

 passing through the West Heath valley, in which a thin bed of 

 water-bearing sand above the clay has produced a swamp, the 

 party visited the residence of Mr. C. Evans, and inspected that 

 gentleman's fine collection of Tertiary fossils. 



The new School of Science and the new Museum and Art 

 Gallery at the rear of the Hartley Mall, Southampton, are fast 

 approaching completion. There are two class rooms of about 

 20ft. by 1 6ft. 6in and i6ft. high, and a large drawing-class room, 

 32ft. by i6ft. 6in. and i6ft. high. In the Art Gallery and 

 Museum are two large rooms, 42ft. by 20ft., and about iSft. 

 high, lighted from the roof and connected with the Science 

 School and the Art School. 



A FREE Museum has lately been opened at Nottingham in 

 Wheeler-Gate. The greater portion of the objects of interest 

 which are in the museum, now the property of the town, origi- 

 nally belonged to the Nottingham Naturalists' Society, and a 

 considerable number of valuable objects were added from time 

 to time until the museum assumed its present dimensions. 



According to the StocklioIm/(/?();/('V(?a'i'i' an important discovery 

 has been made in Sweden. An extensive coal-bed of remarkable 

 depth and excellent quality has been struck near Raus, in Schoncn. 

 An enterprising company formed some time ago was encouraged 

 by promising geological indications to institute borings, but the 

 first resuUs were hardly satisfactory. At a depth of 566ft. 

 eleven strata of coal had indeed been pierced, but none of these 

 exceeded in depth I,', ft. Five feet farther down, however, a 

 bed was struck with a thickness of Sift. The bornigs Iiave 

 been continued, and are believed to prove satisfactorily the 

 existence of an extensive coal-bed. 



A MOST violent cyclone occurred at Madras on May i. Many 

 vessels were driven on shore, and completely wrecked. The 

 pier has been again breached, and great damage done to the city 

 and suburbs. On I'riday, the 3rd, the storm was slightly 

 abating. 



At a recent sitting of the French Academy a letter was read 

 from the French Consular agent at Mostar on the earthquakes 

 felt throughout the Herzegovina during the months of Feljruary 

 and March last. The first was felt on the 6th of February, two 

 days after the great aurora borealis. Other oscillations followed 

 on the 7th and 8th, apparently in a N.W. and S.E. direction 

 On the 13th a longer shock was experienced, followed by a loud 

 rumbling sound like distant cannon. On the 25th and 27th 

 stronger shocks, accompanied by noise, were felt, making about 

 forty since the 6th. On March 2 and 3 the manifestations in- 

 creased in intensity ; but neither Ragusa nor Serajevo, so subject 

 to earthquakes, appear to have been at all affected all the time. 



Some time in the summer of 1871 it was stated that Mr. 

 Octave Pave, a young Louisiana Frenchman, had started toward 

 the North Pole by way of Siberia and Wrangell's Land, and that, 

 in the absence of news from him, the assistance of the Siberian 

 Government had been invoked, in consequence of grave fears for 

 his safety. It now appears that he has not yet started on his 

 mission, but is to sail from San Francisco in May for Kams- 

 chatka, where he will take in supplies, and proceed to Cape 

 Vakan, on the north-east coast of Siberia. Here the vessel is to 

 be abandoned, and a further exploration attempted on an India- 

 rubber raft, composeil of four rubber cylinders fastened together 

 on the decks by wooden slats, to which the masts and rigging are 

 attached. It is intended to head, after leaving Cape Vakan, for 

 Wrangell's Land, a large island discovered by Captain Long in 

 1867. This being reached, the island is to be crossed on 

 sledges ; and if an open sea occur beyond, he is to take the raft 

 again, and endeavour to sail to Greenland or Spitzbergen. The 

 entire enterprise is conducted at the expense of the traveller ; 

 and however hazardous or chimerical the plan may be, we can- 

 not but wish him success in his movements. 



HISTORY OF THE NAMES CAMBRIAN AND 

 SILURIAN IN GEOLOGY* 

 (Continued fioin pa^v 17) 

 YAfHAT then was the value and the significance of the Silurian 

 sections of Murchison, when examined in the light of the 

 results of the Government surveyors? The Llandeilo rocks, 

 having throughout the characteristic Oii/iis so much insisted 

 upon by Murchison, were shown to be the base of a great con- 

 formable series, and to the eastward, in Shropshire, to rest on 

 the upturned edges of the Longmynd rocks ; while w-estward, 

 near Bala, they overlie unconformably the Lingula- flags, and in 

 the island of Anglesea repose directly upon the ancient crystal- 

 line schists. According to the author of the " Silurian .System," 

 there existed beneath the base of the Llandeilo formation a great 

 conformable series of slaty rocks into which this formation 

 passed, and from which it could not be distinguished either 

 zoologically, stratigraphically, or lithologically. The sequence, 

 determined from what were considered typical sections in the 

 valley of the Towey in Caermarthenshire, as given by Murchison, 

 for several years both before and after the publication of his 

 work, was as follows: — i. Cambrian; 2. Llandeilo flags; 3. 

 Caradoc sandstone ; 4. Wenlock and Ludlow beds ; 5. Old Red 

 sandstone ; the order being from north-west to south-east. 

 What then were these fossiliferous Cambrian beds underlying 

 the Llandeilo and indistinguishable from it ? Sedgwick, with 

 the aid of the Government surveyors, has answered the question 

 in a manner which is well illustrated in his ideal section across 

 the valley of the Towey. The whole of tlie Bala or Caradoc 

 group rises in undulations to the north-west, while the Llandeilo 

 flags at its base appear on an anticlinal in the valley, and are 

 succeeded to the south-east by a portion of the Bala. The great 

 mass of this 2;roup on the south-east side of the anticlinal is how- 

 ever concealed by the overlapping May Hill sandstone — the base 

 of the unconformable upper series which includes the Wenlock 

 and Ludlow beds. (Philos. Mag. I\'. viii. 4S8 ) The section 

 to the south-east, commencing from the Llandeilo flags on the 

 anticlinal, was made by Murchison the Silurian system, while 

 the great mass of strata on the north-west side of the Llandeilo 

 (which is the complete representative of the Caradoc or Bala 

 lieds, partially concealed on the south-west side) was supposed 

 by him to lie beneath the Llandeilo, and was called Cambrian 

 (the Upper Cambrian of Sedgwick). These rocks, with the 

 Llandeilo at their base, were in fact identical with the Bala group 

 studied by the latter in North Wales, and are now clearly traced 

 through all the intermediate distance. This is admitted by 

 Murchison, who says : — " The first rectification of this erro- 

 neous view was made in 1842 by Prof. Ramsay, who ob- 

 served that instead of being succeeded by lower rouks to the 

 north and west, the Llandeilo flags folded over in those direc- 

 tions, and passed under superior strata, charged with fossils 

 which Mr. Salter recognised as well-known types of the Caradoc 

 or Bala beds." (" Siluria," 4th ed., p. 57, foot-note.) 



The true order of succession in South Wales was in fact : — 1. 

 Llandeilo ; 2. Cambrian ( = Caradoc or Bala) ; 3. Wenlock and 

 Ludlow ; 4. Old Red sandstone ; the Caradoc or Bala beds 

 being repeated on the two sides of the anticlinal, but in great 

 part concealed on the south east side by the overlapping May 

 Hill or Upper Llandovery rocks. These latter, as has been 

 shown, form the true base of the upper series which, in the 

 Silurian sections, was represented by the Wenlock and Ludlow. 

 Murcliison had, by a strange oversight, completely inverted the 

 order of his lower series, and turned the inferior members upside 

 down. In fact, the Llandeilo flags, instead of being, as he had 

 maintained, superior to the Cambrian (Caradoc or Bala) beds, 

 were really inferior to them, and were only made Silurian by a 

 great nristake. The Caradoc, under different names, was thus 

 made to do duty at two horizons in the Silurian system, both 

 below and above the Llandeilo flags. Nor was this all ; for by 

 another error, as we have seen, the Caradoc in the latter position 

 was made to include the Pentaraerus beds of tlie unconformably 

 overlying series. Thus it clearly appears that, with the exception 

 of the relations of the Wenlock and Ludlow beds to each other 

 and to the overlying Old Red sandstone, which were correctly 

 determined, the Silurian system of Murchison was altogether in- 

 correct, and \\'as moreover based upon a series oi stratigraphical 

 mistakes, which are scarcely paralleled in the history of geological 

 investigation. 



It was thus that the Lower Silurian was imposed on the scien- 

 tific world ; and we may as well ask with Sedgwick, whether 

 ' Reprinted from advance sheets of the Citiindinn Naturalist. 



