Dec. 1 8, 1879] 



NATURE 



165 



appears a, a true quartz-sand, the grains of which are so minute 

 that no interstice can be seen bet een them. It is an excessively 

 compact rock, in which a matrix is hardly appreciable. 



Pyrenees Marble.— In another paper Dr. Barrois gives in- 

 formation regarding the Marbrt GrioUe, now so largely worked for 

 ornamental purposes in the Spanish and French Pyrenees. This 

 roc!;, usually regarded as Devonian, and placed on a parallel 

 with the red limestone of Westphalia and Nassau, is shown by 

 him to rest unconformably on Devonian strata in the Western 

 Pyrenees, to be covered by a Productus limestone of true Car- 

 boniferous date, and to contain in itself a fauna which, by its 

 Crustacea (Phillipia), and more especially by its Goniatiles, must 

 be regarded as Carboniferous. He therefore concludes thit the 

 Griotte limestone or marble constitutes the basement member of 

 the Carboniferous system of the region in which it occurs. 



PErROGRAriiY in Spain.— The progress of petrography is 

 well illustrated by the appearance of an essay on the evolution 

 of volcanic rocks in general and of those of the Canarie ; in par- 

 ticular, by Don Salvador Calderon, of Arana, just published in the 

 Annals of the Spanish Society of Natural History. He reduces 

 all the rocks of the Canary Wands into two grand citegories — 

 a sanidineamphibole group and a plagioclase-augite group. 

 Thus, out of a paste of augite and plagioclase he conceives that 

 all the rocks of the secmd category may have been forme 1, with 

 the addition of other accidental minerals, and by a variation in 

 the proportions. So that at the end of the one series he places a 

 bepheline-basalt containing sanidine, and he traces a gradation 

 from this rock through the disappearance of the sanidine, the 

 successive appearance of hauyne and olivine, and the final 

 predominance of the latter mineral, till he reaches the felspathic 

 basalts, dolerites, and modern lavas. He discusses the evolution 

 of volcanic rocks under four periods: — I. The Lava period, in 

 which section he treats of the vitreous fluidity of lava, the in- 

 fluence of temperature, pressure, and water in the formation of 

 the rock, and the possibility of an arrangement or liquation of 

 the component elements of the lava while still melted within the 

 volcau ). 2. The Refrigeration period. Here he discusses the 

 Crystallisation of the lava, noting particularly the results of the 

 evaporation of the interstitial water, the formation of the 

 "micro-fluctuation" structure, the development of porphyritic 

 crystals, and the effects of sublimation. 3. Changes in the rocks 

 after solidification ; divided into (1) mechanical, which include 

 fractures on the great scale, cracks in the paste of the rocks, 

 fissuring of the crystals, and the formation of cavities and 

 globules ; (2) physical, embracing the phenomena of devitrifica- 

 tion ; and (3) chemical, under which are placed serpentinisation, 

 zeolitisation, natrolitisation, &c. 4. The Decomposition period. 

 Under this he iding the author, citing the researches of Durocher, 

 Bischof, and Delesse on the permeability of rocks by meteoric 

 water, and the changes thereby produced, gives a brief account 

 of the nature of the alterations of some of the more prevalent 

 minerals in the rocks of the Canary Islands and elsewhere. The 

 paper is illustrated by a few drawings of microscopic structures. 



GEOGRAPHICAL NOTES 



Further details are to hand concerning the sojourn of the 

 Russian, Lieut. Tjngin, and a colony of Samoyedes in Novaya 

 Zemlya during last winter and summer. The object of Tjagin's 

 stay on the island was to complete the arrangements for a station 

 for the help of shipwrecked sailors, and to carry out a series of 

 meteorological observations for a whole year. Tjagin arrived 

 at the harbour of Kaimaknl on August 15, 1878. By Septem- 

 ber 13 the nece-sary buildings of wood were completed, and the 

 meteorological instruments installed, and by October 3 all the 

 Samoyedes wore collected about the station. The autumn of 

 1S7S was dull, rainy, and cold. The mean temperature was 

 about 4° Centigrade. The first frost was on September 26. 

 The first snow fell on the 2Sth, and the sea froze on October 10. 

 Ice-crust and drift-ice were seen on the sea in the middle of 

 October, and the harbour of Karmakul, as well as all 

 bay-, were covered with ice on November 13. But Moller Bay 

 did not freeze during the whole winter, except among the islands 

 which lie thick along the coast. The melting of the snow began 

 with the first thaw, about the middle of May, and the first green 

 was seen on the chared spots near to the snow-heaps. On 

 June 14 the islands were covered with verdure and flowers, but 

 the harbour of Karmakul and the little bays were not free from 



ice till July 16, and the small lakes July 22. The mean tem- 

 peratures were in November, — o, 0, 8 C. ; February, — 17°'8; 

 March, -n 0- S. During the five winter months the mean was 

 - 12°"2. In January the temperature sank to -32°'I, and rose in 

 November to + o°'8, and in January to + 0°'2. The move- 

 ment of the atmosphere varied from complete calm, rare mild 

 winds from south-west and north-west, strong winds from east- 

 south-east, rising to raging storms, which greatly impeded hunt- 

 ing operations. The quantity of snow which fell was incon- 

 siderable ; it snowed seldom, but the strong land winds drove 

 the snow from the distant hills and the neighbouring heaps 

 towards the west, and often covered the houses up to the roof on 

 one side, while on the three other sides the snow was blown 

 clean off the ground. Tjagin returned to Archangel on August 

 17 with two orphans belonging to one of the Samoyedes who 

 died during the winter. He maintains that wintering in Novaya 

 Zemlya is quite practicable, especially for Samoyedes. The 

 practicability of erecting a refuge station with provisions ha; 

 also been proved. But a store of provisions is absolutely neces- 

 sary, as it seem; impossible to obtain by hunting anything like 

 a sufficient quantity of animal food during the winter. 



Details have reached this country of the expedition led 

 by Mr. Alexander Forrest into the unknown north-eastern 

 part of Western Australia. Forres left the Beagle Bay, south 

 of King's Sound, on April 20 last, with seven companions and 

 twenty-six horses, proceeded to the mouth of the Fitzroy River 

 in I7°4l'lat. S., and 123° 36' long. E., investigated this un- 

 known river as far as its sources in a mountain ridge 2,000 feet 

 high, in 17° 42' lat. S., and 126° 10' long. E., then followed a 

 tributary to its source in a mountain chain (in 18" lat. S., and 

 127° 40' long. E.), crossed these mountains and discovered a 

 large river in 128° 10 long. E., which he followed for nine 

 miles. The eastern boundary of the colony was reached in 16° 

 50' lat. S., and 129 long. E. Here almost all provisions failed 

 the travellers, yet they proceeded on North Australian ground 

 to the Victoria River, and reached Catherine Station of the 

 overland telegraph (forty four miles south of Port Darwin) on 

 September 18, in a very exhausted condition. Fifteen out of the 

 twenty-six horses had perished, and three more had been killed 

 and eaten. Mr. Forrest reports that he discovered 20,000,000 

 acres of excellent pasture land, of which a large proportion 

 would be well adapted for growing sugar cane, rice, coffee, &c. 

 Water was everywhere in abundance, except on the last twenty- 

 two miles of the march. The numerous natives the party en- 

 countered all behaved in a most friendly manner. 



A telegram from Col. Prshevalski has been received via 

 Pekin. It appears that the traveller and his party reached 

 Shatshkoo at the end of June, after marching through the Shami 

 desert, which in its centre rises to an elevation of 5,000 feet. 

 The oasis of Shatshkoo, situated at an altitude of 3,500 feet, is 

 very fertile. On the south it is bounded by a mountain side 

 which begins at Lake Lob-Nor, and is covered with eternal snow 

 in many" places. The travellers intended remaining on the 

 mountains until the end of July, and then to proceed to Hlassa. 



We have received from the U.S. Survey copies of several new- 

 maps of recently surveyed regions, beautifully finished. They 

 are the Yellowstone National Park, on a scale of two miles to 

 one inch; parts of Western Wyoming, South-eastern Idaho, and 

 North-eastern Utah, and part of Central Wyoming, on the scale 

 of four miles to one inch ; a drainage map of portions of 

 Wyoming, Idaho, and Utah, on the scale of eight miles to an 

 inch. 



Heft I. for 1878-9 of the Mitthdluitgai of the Hamburg 

 Geographical Society, is entirely devoted to Africa. Dr. G. A. 

 Fischer, of Zanzibar, contributes a valuable original paper on 

 the Wapokomo Land and its inhabitants ; Herr A. Woermann, 

 a Hamburg merchant, discusses the products of West Africa from 

 a commercial point of view ; Dr. Hubbe-Schleiden, in a learned 

 and elaborate paper, discusses the Negro's capacity for culture. 



I.\ the December number of Pete: matin's Mitthciiunga:, Dr. 

 Junker describes in considerable detail the results of his journeys 

 in 1877-8 to the west of the White Nile, from Lado to about 

 29° E. long., and south to 3 15' N. lat., results of great 

 importance for a knowledge of a scarcely known region. 



News from Zanzibar announces the safe arrival of the united 

 Belgian expedition at Ugogo. 



