348 



NATURE 



\August 12, 1880 



arrived in tliese parts of space. A searcli for this body with the 

 aid of Trof. Winnecke's sweeping ephemerides is desirable 

 forthwith, the length of the revolution not appearing to be 

 determinable \\ithin very narrow limits from the observations of 

 1S12, and tliere being no other recognised appearance. 



Is 5) Cygni a Variable Star? — Writing in September, 

 1S42, Sir John Merschel drew attention to this star, which he 

 said appeared to have increased very considerably in magnitude 

 since the date of Piazzi's observations. In 1S42 it was "the 

 principal star in the neck of the Swan, and of nearly the fourth 

 magnitude, very conspicuous to the naked eye, and making in 

 fact the only very distinctly seizable point between Albirco in 

 the beak and the bright star 7 in the body." 



Piazzi, who observed the star nineteen times in right ascension 

 and eleven times in declination, calls it 6" 7 m. D'Agelet had 

 estimated it 4-5 on July 29, 17S3, and 5 on September 17, 17S4; 

 Lalande, 5 ou August 12, 1793, and 4 on July 14, 1797; Bes^el 

 in his zone 436 on September 8, 1S28, calls it 3 m. (!) ; Arge- 

 lander and Heis, 4"S. Thus Piazzi's estimate appears to be 

 lower than in the case of any other modern observer, but it is to 

 be noted that Flamsteed reckoned the star no higher than the 

 sixth magnitude. 



1] Cygni seems to deserve some attention at the hands of 

 observers of the variable stars. 



GEOLOGICAL NOTES 



Geology of Belgiuji and the North of France. — M. 

 Mourlon of Brussels has just published a work devoted to the 

 general geology of Belgium. It describes the formations in chro- 

 nological series, and is illustrated with maps, sections, and plates 

 of the microscopic structure of rocks. A useful feature in it is a 

 full bibliography of Belgian geology brought up to date. Tlie 

 new Government Geological Survey of lielgium has just pub- 

 lished three sheets of maps, with sections, and explanatory 

 notices. The ma.ps, on a scale of ^-5^5^, are printed in chromo- 

 lithography and on a novel plan. The ordinary topographical 

 features— roads, fences, trees, houses, &c., are printed in 

 different colours, according to the tertiary formation lying under- 

 neath. Thus the Wemmelien (Eocene) areas are at once 

 recognisable by an orange topography, the Oligocene tracts by 

 one in slate colour and the Anversian (Miocene) by one in 

 crimson. The quaternary deposits overlying these formations 

 are expressed by broad tints of colour. The maps are accom- 

 panied by "Notices Explicatives," which in the case of the 

 Hoboken and Contich sheets appear as a well-printed Svo 

 pamphlet of 256 pages, and a sheet of superficial sections on a 

 scale of Tirrtnr foi' length and y^V^r fof height. The country 

 delineated and described lies on the low ground drained by the 

 Escaut and Rupel, where, as little can be seen at the surface, 

 a large series of borings has been made. The work has been 

 accomplished by the Baron O. van Ertborn, with the co-operation 

 of M. Cogels. Prof. Gosselet of Lille has just issued the first 

 fasciculus of an essay on the geology of the North of France and 

 the neighbouring regions. It deals with the palaeozoic formations, 

 and is accompanied with an atlas of plates of fossils, maps, and 

 sections. No one is so competent as M. Gosselet to describe the 

 older formations of that district which he has so sedulously 

 studied for many years. His volume will be welcomed not only 

 by students in Belgium and the North of France, but by geolo- 

 gists in other countries, who will find in it an admirable rhninJ 

 of all that is known on this subject up to the present time, and 

 references to the more important original memoirs where fuller 

 information can be had. 



The Right of Priority in Pal/eontological Nomen- 

 clature.— M. Gosselet, in a communication to the Societe 

 Geologique du Nord, calls attention to the great inconveniences 

 which arise from the multiplication of names for the same spe- 

 cies. He suggests the estabUshment of an international tribunal 

 for judging of the value of each new species, and for I'Cgistering 

 it, with its name and the exact date of its publication. He 

 thinks that the expenses of the journal of such a commission 

 would be easily met by the subscriptions of scientific men, and 

 that the duties of the commissioners would not be heavy, as 

 they would need to be consulted only occasionally in doubtful 

 cases, the ordinary routine work being performed by a secretary. 

 As illustrations of the evils of the present system, or, rather, 

 want of system, he cites the history of some .Spirifers. 

 ■ -Geological Survey of New Jersey. — Mr. George II. 

 Cook, State Geologist of New Jersey, has issued his unpretend- 



ing but useful Annual Report for 1879. It contains a record of 

 the development of the mineral industries of the State for last 

 year, and is accompanied \vith a good map, on which are 

 delineated the various soils as distributed over the area. The 

 iron-bearing rocks of the Archaean series extend from the north 

 across New Jersey, and for several generations iron has been 

 worked in this State. It is chiefly magnetic ore, and is searched 

 for by means of the compass-needle, the attraction of which is 

 noted. The commercial depression which began in 1873 has 

 told heavily on the u'on manufacture in the State. Of 200 

 mines and localities for ore only thirty have been kept in opera- 

 tion during the wliole period of depression. There are non- 

 hopeful indications however of a revival of the trade. In the 

 midst of information about building-materials, soils, mines, 

 water-supply, and other topics, the writer of the Report con- 

 tinues to find a place for occasional interesting geological facts. 

 His chapters are likely to be of much service to his fellow- 

 citizens, who, it is pleasant to learn, show their appreciation of 

 these Annual Reports, of which many of the former volumes^are 

 out of print. 



Geological Survey of Alabama. — The]|Geological Survey 

 of this State is very modestly equipped. Its director, Prof. 

 Eugene A. Smith, issues Annual Reports, which show, as minutely 

 as the resources at his command will allow, the geological 

 structure and economic resources of the different counties of the 

 State. But he cannot make bricks without straw. It is short- 

 sighted policy to require a Geological Survey to be made, andjto 

 equip it so economically that it caimot efficiently perform its 

 work. In a country where the mineral resources remain in great 

 measure undeveloped, it would be a wise expenditure of public 

 funds to furnish means for making cuttings or borings where the 

 crop of a seam of coal or vein of ore might be revealed at a 

 short distance below the surface. 



Central Asian Geology. — We find in the last number of the 

 Izvesiia of the Russian Geographical Society information as to the 

 geological structm-e of the tracts to be crossed by the Southern 

 Central Asian Railway. Altogether it is a flat and dry desert, 

 covered withrecentalluvial formations; the land becomes hilly only 

 in the Mugojar Mountains. At Orenburg, and as far as Mertvyia 

 .Soli, there appear Trias sandstones and clays, %\iiich cover the 

 Permian limestones, and gypsum with salt-springs (Sletskaya 

 Zaschita). In the neighbourhood of Khanskiy Post we find a 

 formation which probably will have an importance for the rail- 

 way, namely, the Jura, which contains coal. At Ak-tube the 

 shores of Teres-bvutak, Yakshi, and Djaman-kargal Rivers are 

 cr.iggy, and consist of Permian and Trias rocks. The Mugojar 

 Mountains are formed of pretty green and red jades, and the 

 Djaman-tau Mountains of an augitic porphyry of syenite and 

 granite ; gneiss and mica-slate cover the granite on the eastern 

 slope. A kind of fine white clay, being a product of the tritura- 

 tion of rocks, is found at the foot of the Mugojar Mountains on 

 both slopes, and large accumulations of gravel in the form of 

 mounds appear at a short distance from the mountains to the 

 east. The Karakorum steppe affords a series of mounds of 

 sand mostly covered with vegetation and often with vei-y old 

 trees. These mounds are usually motionless, only those which 

 are quite devoid of vegetation (such being exceptional) are set in 

 motion during heavy storms, .\ltogether the structure of the 

 steppe appears thus : At the base a sandstone, probably Tertiar) , 

 horizontally stratified ; above this, a clay with gypsum borrowed 

 liy former watercourses, and above it the sandy mounds.^ Water 

 is found at a small depth. Sandstone and clays forming low- 

 elongated terraces, and belonging possibly to the Jurassic for- 

 mation, appear in the neighbourhood of Kara-tougay on the 

 Syr-daria River. 



Geology of Geneva.— The Geological Map of the Cant.in 

 of Geneva, on the scale of I to 25,000, together with a "Geo- 

 logical Description of the Canton," in two volumes, by Prof. 

 Alphonse Favre, have been pubUshed under the auspices of the 

 Geneva Agricultural Society — the map a year ago, and the "De- 

 scription " only now. The map is \vell printed with eight colours 

 very agreeable to the eye, and sufficiently transparent not to o'-- 

 structthe topographical details. As to the geological value of this 

 work, the name of M. Favre is a sufficient warrant. The learned 

 professor has spent no less than twenty-seven years in the study of 

 the formations of his Canton. The "Description" consists of four 

 parts. The first gives general notions in geology ; the second 

 contains a detailed description of the formations of the Canton, 

 namely, the Molasse, the glacial and the post-glacial deposits 



