88 



HARDWICKE'S SCIENCE-GOSSIP. 



Rising, Southing, and Setting of the Principal Planets, 

 at intervals of Seven Days, for April. 



he has made of the variable star Algol. It appears 

 that the periodic variability of this star is caused by 

 the revolution of a darker companion eclipsing part 

 of its light. The Professor has calculated that the 

 respective diameters of the two stars are about 

 l,oSo,ooo and 850,000 miles, that their centres are 

 distant from each other about 3,290,000 miles, and 

 that the orbital velocity of Algol is about twenty- 

 seven, and its dark companion twenty-seven miles, 

 Algol, speaking roughly, being less than half, and its 

 companion less than one-quarter of the mass of the sun. 



In April there will be no occultations of any stars 

 of large magnitude, nor any astronomical phenomena 

 of popular interest. 



Mercury enters Aries about the nth, and Taurus 

 about the 23rd, and at the end of the month it is an 

 evening star in Pisces. 



Venus is an evening star. 



Jupiter is a morning star. 



OUR SCIENTIFIC DIRECTORY. 



[The Editor will be obliged, if, for the benefit of his numerous 

 readers, secretaries of scientific societies will send notices like 

 the following, also place and time of meeting.] 



T^IRM INGHAM Microscopists' and Naturalists' 

 JZ) Union : President, W. Hillhouse, M.A., 

 F.L.S. ; Hon. Secretaries, Mr. J. Collins, 104 

 Muntz Street ; Mr. S. White, 24 Vincent Street, 

 Balsall Heath. Meets on Monday evenings at 

 1 Broad Street Corner, at 7.30. 



SCIENCE-GOSSIP. 



On Wednesday, March 5th, Mr. Edwin Lucas read 

 an interesting paper before the Civil and Mechanical 

 Engineers' Society (Mr. H. Adams in the chair) on a 

 new medium for Fresco Painting, called "Fresco 

 Cement." The composition, invented by Mr. 

 Kremeyer, consists largely of Tufa, together with 

 Portland cement and lime, and the patentee claims for 

 it that, being hydraulic, absorptive, and acid-proof, it is 

 absolutely unaffected by the severest climate. The 

 author gave a highly interesting resume of the history 

 of the art of Fresco painting, and of the various 

 methods employed by great Italian masters ; by the 

 modern German School, and by artists in this country, 

 dwelling on the great difficulties with which votaries 

 of the art had to contend ; on the elaborate nature of 

 the processes required, and the want of permanence in 

 the completed work. In illustration of the last defect, 

 especially in our climate, he pointed to the fact that 

 English artists had from the twelth century devoted 

 great attention to woiks of this nature, and asked 

 " Where are those works now?" He then proceeded to 

 quote a favourable report from Mr. H.Farja, M.I.C.E., 

 who moreover tested the strength of specimens which 

 had been immersed in water for thirty-three days. The 

 average tensile strength of five specimens was found to 

 be 312 lbs. per square inch. The paper concluded 

 with a practical demonstration of the extreme 

 simplicity of the process by means of the portable 

 fresco-panels which form a striking feature of the new 

 invention. 



Vol. ii. of the "Transactions of the Wagner Free 

 Institute of Science of Philadelphia " contains the 

 following interesting papers : " Report of some 

 Fresh-Water Sponges Collected in Florida," by 

 Edward Potts ; " Notice of some Fossil Human 

 Bones ; " " Description of Mammalian Remains from 

 a Rock Crevice in Florida ; " " Description of Verte- 

 brate Remains from Peace Creek, Florida ;" " Notice 

 of some Mammalian Remains from the Salt Mines of 

 Petite Anse-Louisiana ; " " On Platygonus, an extinct 

 genus allied to the Peccaries," and " Remarks on the 

 Nature of Organic species," all by Professor Joseph 

 Leidy. 



The last number of the " Journal and Proceedings 

 of the Royal Society of New South Wales" contains 

 the following : " Anniversary Address," by Sir Alfred 

 Roberts; "Note on the Composition of Two Sugar 

 Plantation Soils," by W. A. Dixon; " Aborigines of 

 Australia," by W. T. Wyndham ; "Note on the 

 Recent Rain-storm," and " Source of the under- 

 ground water in the Western Districts," by H. C. 

 Russel; " On the High Tides of June 1517th," by 

 John Tebbutt ; " On the Application of Prismatic 

 Lenses for making Normal Sight Magnifying 



