November i6, 191 i] 



NATURE 



87 



Great improvements seem to be possible. Ponies, which 

 once had a high reputation, are now poor; goats and sheep 

 do not bring in anything Hke the profit they might ; whilst 

 the cattle also appear to have deteriorated during the past 

 fifty years. These changes are largely attributed to the 

 large increase in cultivated ground and the consequent 

 reduction in the grazing area. An interesting account of 

 i;rape-growing round Peshawar, accompanied by some 

 ^ood illustrations, is given by Mr. Robertson-Brown. 



The cultivation of cacao is a highly important industry 

 in Trinidad, where also the great bulk of the planters are 

 peasant proprietors. Hence the problem before the staff 

 of the Department of Agriculture is of a dual nature ; new 

 methods have to be worked out for improving yields and 

 coping with pests, and these methods have to be brought 

 to the notice of the grower. In a batch of circulars 

 recently to hand instructions are given in the methods of 

 cultivation calculated best to suit a small proprietor. The 

 entomological and mycological notes by Messrs. Guppy and 

 Urich will be found of more general interest. It is stated 

 that leaf-eating beetles were very common last year, par- 

 ticularly Neobrotica colaspis ; pod-hunters (Horiola 

 arcuata) have also been locally numerous. 



In Bulletin No. 7 of the Commonwealth Bureau of 

 Meteorology the climate of the proposed Federal Capital 

 Territory at Yass-Canberra, in New South Wales, is dealt 

 with. Besides a few preliminary paragraphs, the whole 

 Bulletin is devoted to tables of the mean monthly values for 

 twelve station^, and the average maximum and mean rain- 

 fall for a considerably larger number. Rainfall and tempera- 

 ture data are also shown for an area of about eight square 

 degrees on a map, which might conveniently have been on 

 a smaller scale, the isotherms being drawn in by interpola- 

 tion from the twelve observing stations and by employing 

 corrections of 1° F. for each 300 feet of altitude and each 

 degree of latitude. No. 8 Bulletin of the same Bureau 

 deals with the physiography of the same area. Mr. G. 

 Taylor treats by the modern explanatory method the land- 

 forms for a radius of about 20 miles round Canberra. 

 Various parts are first described in their present condition, 

 after which the past development of the region is worked 

 out. An ancient peneplain was uplifted for some 800 feet 

 and then maturely eroded, after which a period of unrest 

 set in, during which blocks have been tilted, and the 

 drainage system thereby considerably modified, numerous 

 cases of river-capture occurring. The report is illustrated 

 by sketch-maps and diagrams, and gives a good idea of 

 the area, which would have been improved by a short 

 general description of the main features of this part of 

 New South Wales. 



In Heft No. 9 of the Mitteilungen der k.k. Geo- 

 graphischen Gesellschaft of Vienna an account is given of 

 the May cruise of the surveying ship Najade. Soundings 

 were taken o^i the line Brindisi-Durazzo, and the con- 

 siderable depths which observations in 1877 had indicated 

 were not borne out. In lat. 41° 15' N. and long. 18° 15' 

 previous soundings of 1500 and 1600 metres are replaced 

 by more correct values of from 1000 to 1100 metres. The 

 greatest depth of the Adriatic, hitherto given as 1645 

 metres, is now to be taken as 1132 metres somewhat to 

 the north of the point previously indicated in the basin 

 between Novi and Cattaro or Ragusa. A brief summary 

 of the biological work is also given. 



In the November number of The Geographical Journal 

 there appears a map of Africa on which are shown in 

 different grades of colour the portions systematically 

 surveyed, those mapped by good route traverses, and the 



NO. 2194, VOL. 88] 



areas which are but roughly mapped or known only by 

 report. While the second class covers a large area, 

 systematic survey is limited to frontier lines and to areas 

 in Algeria, Egypt, Uganda, South Africa, and a few other 

 points. There still remain vast areas both for exploration 

 in its true sense and for systematic study, and if a corre- 

 sponding map had been prepared to show our knowledge of 

 the continent from other points of view than its topography 

 the scope for investigation would be seen to be even wider 

 than appears from the present map. 



In the Zeitschrift der Gesellschaft fiir Erdkundc (No. 7) 

 Prof. K. Kretschner completes his survey of the manu- 

 script maps of the National Library at Paris. These date 

 mostly from the sixteenth and seventeenth centuries, and 

 are of the class known as compass charts or portolan 

 maps. While some bear the name of the author, many 

 are anonymous ; and maps of both classes are described in 

 the present article, which deals only with those hitherto 

 unknown or which have been very imperfectly treated. 

 The investigation was undertaken in order to improve our 

 knowledge of this portion of early cartography by examin- 

 ing, so far as possible, all the maps preserved in different 

 countries or cities, as has been very completely done for 

 Italy and largely carried out in Germany. 



The October number of Le Radium contains a short 

 note by Madame Curie on the variation with time of the 

 activity of some radio-active substances. The measure- 

 ments have extended over several years, and the results 

 given have been standardised by the use of the piezo- 

 electric charge on quartz. The black oxide of uranium 

 tested for four years in an ionisation chamber in which 

 the whole of the o radiation was absorbed showed no 

 change. Actinium showed a decrease of activity of about 

 10 per cent, in three years ; and Madame Curie assigns to 

 it a mean life of thirty years. Radium, purified from 

 emanation and from traces of radium D, E, and F, was 

 tested by means of its ;8 and 7 radiation, and found to 

 increase in activity 5 per cent, in two years. Madame 

 Curie attributes this increase to the formation of radium E. 

 Radium D, purified from radium E and F, appears to have 

 a life of about twenty-five years. The measurements are 

 being continued so that the changes observed in succeed- 

 ing years may be determined. 



In the July number of the Tokio Sugakti-Buturigak- 

 kwai Kizi Mr. S. Nakamura describes a panoramic camera 

 by means of which the whole horizon (360°) can be photo- 

 graphed on a stationary film, which is hcui into a cylinder 

 and suitably supported inside the cani( 1,1 w.ill. In order 

 to get the image on the film it is necessary to have two 

 reflecting surfaces parallel to each other and inclined at 

 an angle of 45° with the vertical axis of the camera, the one 

 above the camera to receive the light from the view, and 

 the other within to receive it from the upper mirror and re- 

 flect it to the film. The lens may be horizontally in front 

 of either of the reflectors or vertically between them, and in 

 making an exposure the complete optical system revolves 

 on its vertical axis. The chief optical condition necessary 

 in all such apparatus is that the second nodal point of the 

 objective must be at the centre of rotation, and in this case 

 in the centre of the camera. With ordinary photographic 

 objectives, in which the nodal points lie within the objective 

 itself, it is difficult, if not impossible, to fulfil this con- 

 dition in these circumstances. The author therefore uses 

 a lens which consists of a negative as well as a positive 

 combination, as in telephotographic lenses, so that the 

 nodal points aro thrown well outside the objective ; it is 

 then only a m.iiii r of construction to fulfil every necessary 



