July 19, 1883] 



NATURE 



281 



mineral waters. There are 1027 sources which are worked. Of 

 these 319 are sulphurous, 357 alkaline, 136 iron, and 215 salt ; 

 386 are cold, that is to say, they do not exceed 15° C. in tem- 

 perature, and 641 are thermal. They are distributed as follows : 

 — Puyde-Dome, 94 ; Ardeche, 77 ; Vosges, 76 ; Ariege et 

 Pyrenees Orientales, 69 ; Hautes- Pyrenees, 64. The paper also 

 states the number of visitors to these different waters. It appears 

 that the Hautes-Pyrenees are the most frequented. During the 

 past year this department alone has had 44,476 visitors, thus dis- 

 tributed : — Puyde-Dome, 18,619; l'Alliers, 16,430; la Haute- 

 Garonne, 14,230; les Landes, 12,954. The water flowing from 

 all the 1027 sources is estimated at 46,412 litres per minute. 



The Chevalier Frederic Franchetti, engineer at Leghorn, has re- 

 ferred M. de Parville to a curious passage in Galileo's " Dialogues" 

 touching a possible early origin of the electric telegraph. In the 

 dialogue Sagrado says that he calls to mind a man who wanted 

 to tell him a secret which would give him the power by means 

 of a certain sympathy of magnetised wires to speak to any one 

 two or three thousand miles off. The bargain however fell 

 through, as the inventor would not try any shorter distance, and 

 Sagrado declined to go to Cairo or Muscovy to try the experi- 

 ment. The story is told in the last number of the Revue Scioi- 

 tifique. The reference given is p. 97 of the first day, Leghorn 

 Edition, 1874. 



The Executive Committee of the International Fisheries Ex- 

 hibition has published a penny plan and tour as a complete 

 guide to the leading and most interesting features of the Exhi- 

 bition, which we think will prove useful. 



We have some very interesting figures before us comparing 

 the different modes of illumination in respect to the amount of 

 products of combustion : — 



Products per hour. 



W.-iler 

 Light of 100 candles. 



Electric lamp, arc 



,, ,, incandescent . 



Gas, Argand burner 



Lamp, petroleum, flat flame. 



„ colza oil 



Candle, paraffin 



,, tallow 



Thee we think are quite sufficient to show the great supremacy 

 of electric lighting over all other methods of illumination when 

 considered as a matter of health. 



We learn from Natural that a hitherto unknown form of the 

 potato disease, which had been making slow but steady pro- 

 gress near Stavanger during the last ten or twelve years, has 

 recently begun to show increased energy. Tne stalk of the plant 

 is the part affected, and here Herr Anda has discovered .'mall 

 white fungoid growths, which after a time assume a greenish, 

 and finally a black, colour, after attaining the size of a small 

 bean. While the fungus is rapidly increasing at the expense of 

 the plant, the interior of the stem is first reduced to a pulpy 

 condition, and next shrivelled and hollowed out, until nothing 

 remain-; but a mere outer shell, which breaks down on being 

 touched. When the ripe black germs of the fungus have re- 

 mained in the earth through the winter, they are found after the 

 return of the next year's warmth to have developed small stalked 

 fruits filled with minute spores, which penetrate into the young 

 plants before they appear above the ground. The end of July 

 or beginning of August is the time when the ravages of the 

 fungus are most conspicuous, and at those periods whole fields 

 of potato plants are often rapidly reduced to the condition of 

 withered straw. 



We have received from the Minister of Mines of New South 

 Wales the report of the Chief Inspector of Mines for the year 



1882. Besides the usual statistics, a great part of the report 

 is occupied with suggestions for the improvement of the present 

 law of the colony for preventing accidents to workmen in mines. 



From a comparison between the lists of birds observed at Salt- 

 dalen in Norway by the ornithologist Sommerfelts, from 1805 

 to 1825, and those which are now found in the district, it would 

 appear, according to Herr Hageman of the Norwegian Forest 

 Department, that the smaller singing birds are much more largely 

 represented now than formerly. The ortolan and crossbill, 

 Hirundo urbica and rustica, the common sparrow and the 

 chaffinch, which are now abundant, were then unknown in the 

 district, while the common sparrow was only observed on one 

 occasion by Sommerfelts. Herr Anda ascribes the present in- 

 crease in numbers and species to the better cultivation of the 

 land and the clearing of the fir- woods. 



The additions to the Zoological Society's Gardens during the 

 past week include a Kinkajou (Ccirolcptcs caudivolvulus) from 

 South America, presented bj Mr. II. V. Brackenbury ; a Syrian 

 Fennec (Canis famelicus 9) from North Africa, presented by 

 Mr. J. H. James; a Blau-bok {Cephaloplms pygnueus 9) from 

 South Africa, presented by Mr. Ernest Honey ; a Slender-billed 

 Cockatoo {Licmetis Unuiroslris) from Australia, presented by 

 Mrs. A. C. Biddle ; an Earl's Weka Rail (Ocydromiis carlii) 

 from North Island, New Zealand, presented by Mrs. Wilson ; 

 two Wood Owls (Syrnium aluco), British, presented by Mr. J« 

 Metcalfe ; two Black Guillemots [Uria grylle) from Ireland, pre- 

 sented by Mr. H. Becher ; a Vervet Monkey {Cercopithcats 

 lalandii £ ) from South Africa, a Moor Macaque (Macacus 

 mounts <5 ), a Bonnet Monkey {Macacus radiatus 9 ) from India, 

 two Common Snakes (Tropidonotus natri.x, var.), European, a 

 Spotted Cavy (Ctrlogenys paca), two Hairy-rumped Agoutis 

 {Dasyprocta prymnolopha) from Guiana, deposited; a Black 

 Hosier [Myceies caraye a ) from Brazil, purchased ; a Japanese 

 Deer (Cervus sika £ ), a Burrhel Wild Sheep (Ovis burrhel 9 ), 

 born in the Gardens. 



OUR ASTRONOMICAL COLUMN 



The Total Solar Eclipse of August 28-29, 18S6. — 

 This great eclipse is a return of that of {August 17-18, 1868, 

 which was extensively observed in the Bombay and Madras 

 Presidencies and in other parts of its track from Aden to Torres 

 Straits. In 18S6 the track of the central line is mainly over the 

 Atlantic Ocean, and at that portion of it where the duration of 

 totality is longest it will not be observable on land. It is there- 

 fore of interest to examine the possible conditions of observation. 

 In deducing the re-ults which follow, the places of the sun and 

 moon have been taken from the Nautical Almanac, where New - 

 c imb's corrections to Hansen's Lunar Tables are introduced. 

 As will be seen from the Ephemeris, the central eclipse com- 

 mences in longitude 79° 46' west of Greenwich, and latitude 9 

 48' north, off Colon, in the isthmus of Panama, thence running 

 in the direction of the Windward Islands across the northern 

 parts of New Grenada and Venezuela ; passing over the Island 

 of Grenada, it traverses the Atlantic, and meets the coast of 

 Africa in the Portuguese possessions, not far from St. Philip de 

 Benguela, and crossing South Africa to Sofala, it ends on the 

 east coast of Madagascar. At Cartagena the duration of totality 

 is 3m. 2s., with the sun at an altitude of 5 ; at Maracaybo the 

 duration is 2m. 57s., with the stm 9 above the horizon. The 

 southern extremity of the Island of Grenada will have the 

 most advantageous conditions for observation, having regard 

 to length of totality and accessibility. The total eclip.se 

 begins there at 7I1. Iim. os. a.m. on August 29, and 

 continues 3m. 42s., the sun being at an altitude of 20° ; 

 at the northern extremity of the island the length of total 

 eclipse is about five seconds less. In Carriacou, the principal 

 island in the Grenadines, the duration of totality is 3m. 

 2IS. ; at the northern point of Tobago it is Im. 51s. On 

 the Atlantic, where the sun is on the meridian at the middle of 

 the eclipse, or in longitude 14° 27' west and latitude 2° 57' north, 



