August 6, 1896J 



NA rURE 



527 



Ilellmann makes up for its slenderness by means of a short 

 biograpliy of Hadley, and several helpful and interesting notes. 

 The reprints are published by Messrs. A. Asher and Co. 



The foiniml of Bolany reprints some very interesting extracts 

 from Mr. T. Kirk's presidential address to the Wellington (New 

 Zealand) I'hilosophical Society, on the displacement of native 

 by introduced species of plants. Next to man, the chief agents 

 in this destructive work in New Zealand are sheep and rabbits, 

 but the black rat has also had his share. " Some districts are 

 eaten almost bare by these close feeders, little being left except 

 the tough bases of Poa acspitosa and the wiry ligneous stems of 

 Miihleiiheikia, and similar plants : even the woolly leaves of 

 some species of Cehnisia are often closely cropped, the result 

 being that the more delicate plants are all but extirpated over 

 large areas." Introduced plants like Sitene anglica, Erigeron 

 (aiiaJeinis, Kumex obtiisifolitis and crispus, Broinus sterilis, 

 and Hokus lanattis, have almost driven out the original littoral 

 vegetation in some districts. Even more destructive are the 

 ravages caused by the parasites, animal and vegetable, which 

 some of these strangers bring with them. Some idea of the 

 extent of this invasion may be gathered froin the fact that the 

 first catalogue of naturalised plants in New Zealand, published 

 in 1855, comprised forty-four species ; while at the present time 

 Mr. Kirk is himself acquainted with 304 .species, while others 

 put the number at 3S2. 



We have received the first number of vol. iii. oi Poggeiidorff's 

 Biographisch-Lilerarii<hes Handwortcrbiich der Exacten Wis- 

 seiischa/teit (J. A. Earth, Leipzig), which is to contain short 

 biographical notices of mathematicians, astronomers, physicists, 

 chemists, mineralogists, geologists, geographers, &c., living 

 within the period 1858-18S3. The first number extends from 

 " d'Abancourt " to " Beilstein," and the whole volume will 

 contain about fifteen numbers, appearing at intervals of six 

 weeks (35. each). The times preceding 1S58 have already been 

 dealt with in the first and second volumes (price 285-.), and any 

 gaps which have been discovered since will be filled up in the 

 present volume. A fourth volume is to cover the years from 

 1883 to 1900. The whole work will be a monument of careful 

 compilation, and will do much to unify the world of science. 

 The plan of the work is admirably designed. Short biographical 

 notices are followed by a detailed enumeration of the papers and 

 books contributed to scientific literature. Among the men of 

 this first number, Sir G. B. Airy Ksfadlc princeps in the volume 

 of his writings, as the four closely-printed columns of titles 

 testify. There are many Arabian and other philosophers who 

 arc now seldom heard of, such as Abraham ibn Esra of Toledo, 

 .\1 Marokeschi of Marocco, and Al Mahani of Khorasan, which 

 this dictionary preserves from unmerited oblivion. Taken as a 

 whole, the dictionary appears to be highly trustworthy, and the 

 print and paper leave nothing to be desired. 



In the current number of the Coiiiptes reiiJiis there is an 

 account, by .M. H. Moissan, of some further experiments on the 

 preparation of the diamond. With the view of obtaining the 

 greatest possible pressure upon the solution of carbon in iron 

 during solidification, the cooling with mercury or other metal was 

 arranged in such a manner that small spheres from 5 mm. to 

 10 mm. in diameter were produced. These spheres gave 

 specimens both of the black and transparent varieties of 

 diamond, which, although very small (O'OI to 0'02 mm.), were 

 remarkably regular and perfect in shape, agreeing exactly with 

 the forms found in nature. 



The additions to the Zoological Society's Gardens during the 



past week include a Rhesus Monkey (Macacus rhesus, 9 ) from 



India, presented by Mr. V. Lloyd ; two Amaduvade Finches 



(Estrclda amandava) from India, a Paradise WTiydah Bird 



NO. 1397, VOL. 54] 



{Vidua paradisca) from West Africa, presented by Miss M. von 

 Laer ; a Raven (Coi-i'us torax), British, presented by Mr. A. H. 

 CuUingford ; a Martinique Gallinule {louoriiis martini, us) from 

 South America, presented by Mr. \. W. Arrowsmith ; a Cape 

 Viper (Caucus r/iombeatus), s^VaS AAiei [Vipcra arid/aiis), a. 

 Cape Bucephalus {Bucephalus capensis), five Hoary Snakes 

 (Coronella cana), a Ring-hals Snake {Sepedon hceinachates], four 

 Crossed Snakes {Psammophis crucifer), six Rufescent Snakes 

 Leplodira rufesceiis), three Rough-keeled Snakes [Dasypeltis 

 scabra), four Rhomb-marked .Snakes {Psammophylax rhoin- 

 bealus), a Delaland's Lizard (Nucras delalandii), a Defenceless 

 Lizard {Agama iiierinis) from South Africa, presented by Mr. 

 J. E. Matcham ; four Midwife Toads (Alytes ohstelricans). 

 South European, presented by Prof. Gustave Gilson ; a Gentoo 

 Penguin (Pygosceles i,eiiia/us) from the Falkland Islands, de- 

 posited ; eight Amherst Pheasants {Thauinalea aniherstiic), two 

 Peacock Pheasants {Polyplcctron chiiu/uis), two Himalayan 

 Monauls {Lophophorus iinpeyaiius), bred in the Gardens. 



OUR ASTRONOMICAL COLUMN. 



The Planet Saturn — In the Aslronomische Nachrichten, 

 No. 3365, Prof. Barnard comments upon the accounts of various 

 new markings on the rings and body of this planet. In com- 

 pany with Profs. Burnham and Hough, he carefully examined 

 Saturn with the i8i-inch refractor at Dearborn Observatory. 

 The planet was in a good position for seeing, being on the 

 meridian, and during the evening several difficult double-stars 

 were accurately measured. In spite of this, no abnormal features 

 could be discerned, either on the globe or on the rings. The 

 recently reported observations of new divisions, ragged edges 

 to the crape-ring, &c. , were all invisible. In fact the planet 

 appeared very similar to what Prof. Barnard usually saw with 

 the 36-inch Lick, although the latter, with its larger aperture, 

 made the identification of details less difficult. 



New Nebulosity in the Pleiades. — W. Stratonoft', in 

 the Astronontisclie Nachrichten, No. 3366, describes the results 

 of recent long-exposure photographs of the Pleiades, taken 

 with a refractor of 13 inches aperture. Three photographs 

 are mentioned, obtained with exposures of gh. 54m., 

 I7h. 36m., and 25h. The first two shosv most of the known 

 nebulosity, but the third shows the existence of several new 

 features. The chief of these is a long straight streak of 

 nebulosity extending from o = 3h. 407m., 8 = +24° 4' to 

 a = 3h. 41 -gm., 5 = -t- 24° 4', roughly about 20' north of 

 Alcyone. The breadth of this is from 20" to 30" ; it is almost 

 parallel to the neighbouring line of nebulosity described by 

 M. M. Henry, and has a very similar form. 



Another slight nebulosity is visible on the plate near the star 

 1 8m., in the form of several filaments lying north and south, 

 and varying in breadth from one to three minutes of arc. 



New Variable in Hercules.— Mr. T. D. Anderson, of 

 Edinburgh, gives in the Astronomiscke Nachrichten, No. 3366, a 

 description of his observations of a 9th magnitude star, leading 

 to the discovery of its variability. This is the star B.D. + 

 2y°'2T;2, whose position for i855'o is given as R.A. = 

 I7h. 4m. 58-45., Deck 4- 27° i4'-3. The star could not be 

 found in September 1895, using a 2i-inch refractor, but in 

 October of the same year it was easily seen with the same 

 instrument. Taking two neighbouring stars of magnitude 8-8 

 and 9-6 for comparison, he found the variation in magnitude to 

 be from 9'2 to below 10 in about a month. In July 1S96 he 

 again found the star to be invisible as in September 1895, 

 although the neighbouring 9-6 magnitude star was easily seen 

 again. 



THE INSTITUTION OF MECHANICAL 

 ENGINEERS. 

 HE annual summer meeting of the Institution of Mechanical 

 Engineers was held last week in Belfast, commencing on 

 Tuesday, July 28, and concluding on Friday, July 31. There 

 were two sittings for the reading and discussion of papers, the 

 following being a list of those presented :— 



T 



