372 



NATURE 



[February 15, 1900 



amount of free air meteorological observations taken in the 

 same space of time, and is a valuable contribution to the 

 general knowledge of the physics of the lower levels of the 

 atmosphere. The mean rate of diminution of temperature with 

 increase of height, as determined from 121 7 ascents to 1000 feet 

 or more, was 5°o for each 1000 feet. The largest gradient, 

 7°-4 per 1000 feet, was found up to 1000 feet, after which there 

 was a steady decrease up to 5000 feet, the rate becoming less 

 as the altitude increased. The gradient up to 5000 feet was 

 3° -8 per 1000 feet ; above this altitude there appears to be a 

 tendency to a slow rise. The relative humidity at and above 

 the surface of the earth differed but little, except at 7000 feet, 

 where the surface humidity was 11 per cent, less than that 

 above. The mean result obtained from all the observations 

 showed 60 per cent, at the surface and 58 per cent, above, a 

 difference only of 2 per cent. The work contains an important 

 introductory paper, by Prof. C. F. Marvin, on the construction 

 and operation of the kite meteorograph. 



Dr. K. Danilewsky has sent to the Scientific American 

 some interesting photographs and particulars of the latest im- 

 provements he has made in his balloon-flying machine. The 

 €xperiments were conducted under the auspices of the Russian 

 Government in order to give the inventor an opportunity of 

 •demonstrating the practicability of this dirigible air-ship, and 

 its feasibility for use in the Signal Service Corps of the Russian 

 Army. The balloon is shown descending in the accompanying 

 picture. It is filled with pure hydrogen, and its comparatively 

 small size makes it easy to manage, three or four men being 

 sufficient to start it, and half an hour long enough to fill it with 



The Danilewsky Dirigible Balloon. 



gas. The balloon possesses sufficient force of ascension, or 

 levity, to neutralise the weight of the man and tackle suspended 

 from it. The work done by the aeronaut may thus be entirely 

 devoted to propelling and steering the balloon, apparently by 

 means of wing-systems, which are not described in the Scientific 

 American, but may be seen in the illustration. At one of the 

 trials of this flying-balloon. Dr. Danilewsky a.scended from a 

 NO, I581, VOL. 61] 



certain place, disappeared from view and remained cut of 

 sight for two hours, and then returned close to the shed from 

 which the balloon started. The experiments have induced a 

 number of Russian experts to state that in their opinion Dr. 

 Danilewsky has presented a practical solution of the problem 

 of aerial navigation. 



The Botanical Garden at Buitenzorg, Java, has followed the 

 example of that at Kew, and those of some of our ColcMiies, in 

 bringing out a Bulletin in addition to the well-known Annales. 

 The issue of the Biiilelin of the Boissier Herbarium at Geneva 

 has been discontinued, and its place will be taken by Mt'moires 

 dd VHerbier Boissier, to be published at irregular intervals. 



We have received the first number (January 1900) of the 

 Journal of the New York Botanic Garden, edited by the 

 Director of the Laboratories, Prof. T. D. Macdougal. It com- 

 mences with an account, accompanied by an illustration, of the 

 Museum Building, which claims to be " the largest, most 

 elegant, most satisfactorily illuminated, and for its purposes the 

 best adapted, of any similar edifice in the world." A descrip- 

 tion is given of the structure of the building, of its lecture- 

 theatre, museums, library, and laboratories. The General 

 Museum is designed to exhibit types of all the families and 

 tribes of plants, from the slime-moulds or Myxomycetes to the 

 Compositee ; and an interesting feature of the collection is that 

 fossil plants are shown along with the living ones to which they 

 are most nearly related. Then follow short papers on com- 

 parative forestry ; on etiolated plants as food ; on mycorhizas of 

 orchids, in which it is stated that the roots and underground 

 organs of every one of more than seven hundred species ex- 

 amined were found to be infested by symbiotic fungi ; and on 

 colours. 



We have received the fifth number of another new Argentine 

 scientific journal, Comiinicaciones del Museo Nacional di 

 Buenos Aires. To this part Seiior Ameghino contributes an 

 illustrated account of a small skull from the Parana deposits 

 described last year under the name of Arrhinolemur, and now 

 regarded as indicating a new order of mammals allied to the 

 Lemurs. This skull, which is remarkably short and broad, pre- 

 sents the unique feature of having the nasals soldered together 

 and placed in a cleft between the maxillae and the premaxillae in 

 such a manner that, according to its describer, there is no nasal 

 aperture ! Another peculiarity is the presence of a preorbital 

 vacuity in the cranium, and of an unossificed space on each side 

 of the deniary portion of the lower jaw ; in both of which re.'pects 

 it resembles the skulls of certain reptiles and birds. If rightly 

 described, and really mammalian, the specimen is of surpassing 

 interest, and demands the best attention of systematists. In 

 another article in the same journal, Strior Mercerat contributes 

 his quota to the already teeming literature on the "last of. 

 the ground-sloths" {Neomylodon or Glossotherium), in the 

 course of which he severely criticises the determinations made by 

 his countrymen of some of the associated remains of other 

 animals. 



The Report for 1899 on the Lancashire Sea-fisheries Labor- 

 atory at University College, Liverpool, and the Sea-fish 

 Hatchery at Piel, drawn up by Prof. Herdman, contains a very 

 important account of the common cockle by Mr. J. Johnstone, 

 who treats his subject both from the zoological and the economical 

 ; point of view. The anatomy of this mollusc is very fully 

 described, with .some excellent figures ; but the chief general 

 interest centres on the economical aspect. Cockles form the 

 food of several kinds of valuable fishes, more especially the 

 plaice and the dab, while vast numbers are said to be consumed 

 by the larger sea-birds. And we have a remarkable instance of 

 how protection afforded to one group of animals reacts on 



