18 



SCIENCE. 



[Vol. I., No. 1. 



which he regards as a natural one ; and, although many 

 will not be disposed to agree with him, it contains 

 certain elements of value. 



f Cnstogenous ( gj-ts. 



loots. (Conglomerates. 



Denterogenous 1 Psammogenous ( gand^tone. 

 rocks. 1 rocks. | Q„artzite. 



Ti i Earthy rocks. 



Ilyogenous Schistose rocks. 

 I. locks. ( Lithoidal rocks. 



f Phanerozoic liraestonus. 

 J Microzoic limestones. 

 ] Clastozoic limestones. 

 [Crypozoic limestones, 

 '"liceous microntogenouB 

 rockB. 



3rrugineouB microntoge- 

 nous rocks. 

 rFossil resins. 

 ! Bitumens. 

 ] Fossil carbons. 

 (Vegetable eartbs. 

 \ Saline rocks. 

 I Gypseous rocks. 

 I Incrustations. 

 ! ConcroLions. 

 ( Pisolites. 



i Quartz, calcite, siderite, 

 \ barite, fluorite, pbospho- 

 ( rite, etc. 

 f Trachytic lavas. 

 f Cbysiogenous 1 Basaltic lavas. 



Pyrogcnous J ™«>^- jgrSti^'i^. 



( Volcanic breccias. 

 ) Volcanic tuflfas. 

 j Granitic rocks. 

 } Syenitic rocks, 

 i Aluminio-alkaline schists. 

 Magnesian schists. 



Athrogenous 

 [ rocks. 



{Grjinitoid rocks 

 Crystalline 

 schists. 



[Arch. sc. phys. nat., 1S82, July 1.5.) M. B. w. [21 



Meteorites. 



The Dre.sdeu meteorites. — A. Purgold gives a 



list of the forty-five speciraens of meteorites in tlie 



Dresden museum, adding a brief description of each 



specimen. Following Tschermal^, the meteorites are 



arranged according to the following classification : — 



I. Meteoric stones. 



1. Anorthite and augite. Iron rarely seen. 



Eukrite. 



2. Olivine, bronzite, enstatite. Iron rarely 



seen. 

 .3. Olivine and bronzite with iron. Chondrite. 

 II. Meteoric iron. 



4. Silicates and meteoric iron forming a granu- 



lar mixture. Mesosiderite. 



5. Meteoric iron porphyritically enclosing crys- 



tals of silicates. Pallasite. 



6. Meteoric iron. 



{Abhandl. cjeselhch. Ms, 1882. ) M. E. W. [22 

 The Pallas iron. — Dr. Stanislas Meunier has 

 made a recent study of a specimen of the celebrated 

 iron olivine meteorite found by Pallas at Krasnjarsk, 

 Siberia. He regards tlie structure of this meteorite 

 as a vein-form similar to the terrestrial veins com- 

 monly known as filons en cocardes. The pyri-hotite 

 in this he seems to regai-d as derived from the nickel- 

 iferous iron by the action of sulphuretted hydrogen. 

 On account of tliis derivation, he claims that this me- 

 teorite sliould be separated from the others enclosed 

 under the pallasiles by Gustav Rose. — {Comjjt.es 

 rendus, xcv. 938. ) m. e. w. [23 



Fusion-structures in meteorites. — In this ab- 

 stract Mr. F. G. Weichmann holds that the supposed 

 organic forms described by Dr. Otto Hahn from 

 meteorites are 'fusion structures,' that is, formed 

 by the cooling of the meteorite from a state of fus- 

 ion. This view was taken by Prof. Kengott in 1868, 



when he described these structures in the Knyahiiiya 

 meteorite, the one in which Hahn found most of his 

 so-called meteoric corals, crinoids, etc. Judging from 

 the abstract, the completed paper of Weichmann will 

 contain much interesting matter. — ( Trans. iV. Y. 

 acad. sc, 1882, i. 15:-5.) m. e. w. [24 



METEOKOLOGY. 



The hurricane of Oct. 20, 1882. — The observa- 

 tory of Manila has puljlished a small monograph 

 containing a detailed account of this disastrous storm. 

 It is rare that a storm of this nature passes so near 

 an observatory equipped with self-recording instru- 

 ments, as in this instance. The centre of the storm 

 moved almost exactly over Manila, which gives tliis 

 report peculiar value. It contains a chart of the 

 records of the several meteorological instruments, 

 and diagrams illustrating the progress of the hurri- 

 cane. The observations recorded as the centre of the 

 depression was passing are especially noteworthy. 

 The pressure experienced a rapid f.all of 24 millime- 

 tres in Si liours, and a correspondingly rapid rise; 

 the temperature rose from 25° to 31° C. in forty-five 

 minutes, and fell with equal rapidity; while the rela- 

 tive humidity dropped from 100 to 53 per cent in the 

 same short time, and rose again. The velocity of 

 the wind, which was 54 metres per second (about 

 120 miles per hour) immediately before and after 

 the passage of the centre, was for two minutes only 

 before the change of its direction. The diameter of 

 the vortex was about 15 miles, and its velocity of 

 trauslatinn 19 miles an hour. — w. v. [25 



[An abstract of the Jesuit observations with fuller 

 details and diagrams is given in another part of this 

 week's issue.] 



Exposure of thermometers. — Experiments 

 made by Dr. Gill at the Cape of Good Hope, with 

 the Stevenson shelter, Glaisher stand, and a window 

 screen, show large differences in the records of maxi- 

 mum and minimum temperature. An extreme dif- 

 ference of 9.2° is found in the annual value for 1881 

 of the range between the maximum .and minimum 

 readings. Experiments made by Rev. F. W. Stow, 

 with the Stevenson and metallic shelters, favor the 

 latter; but care was not taken to have the shelters 

 of the same size, and tlie instruments similarly 

 placed within them. There is much need of atten- 

 tion to the subject of uniformity of thermometer 

 exposure, especially in this country. — {Quart, journ. 

 meteor, soc, July, 1882.) w. u. [26 



The aurora. — M. Angot considers that the past 

 records of auroral phenomena distinctly indicate 

 diurnal, annual, and secular periods. His researches 

 confirm the electrical theory of tlie origin of the 

 aurora, as elaborated by Edlund. — (Lwa. electr., 

 Dec. 16, 23, 1882. ) w. u. [27 



PHYSICAL GEOGRAPHY. 

 Terraces and beaches about Lake Ontario. — 



J. W. Spencer continues his studies in Canada in the 

 region of the former connection of Lakes Erie and 

 Ontario, and finds evidence of post-glacial lake-sub- 

 mergence 1,700 feet above present sea-level : the Great 

 Lakes must then have been confluent, and connected 

 with the sea by several outlets, — St. Lawrence, Mo- 

 liawk, southward from Cayuga and Seneca Lakes, 

 and by several paths southward across Ohio. The 

 beaches corresponding to the level of these old outlets 

 are believed to be the most conspicuous and wide- 

 spread. The ' Artemesia gravel ' is regarded as a shore 

 deposit of the subsiding lake. Shore-ice is considered 

 an important agent in building the beaches. — {Amer. 

 Journ. sc. , Dec, 1882.) w. M. D. [28 



