132 



NATURE 



[June 9, i; 



Meteorological Relations between the North Atlantic Ocean 

 and Europe during the Winter Half-year," based upon a much 

 longer series of observations. The results confirm those of Dr. 

 Pettersson in a very satisfactory way, and show that a good 

 idea of the temperature over a large area may be predicted with 

 a considerable probability of success, and that, generally speak- 

 ing, a high (or low) temperature of the Gulf Stream on the 

 Norwegian coast in the first part of the winter (November to 

 January) is usually followed by a high (or low) air-temperature 

 in Central Europe in the latter part of the winter (February to 

 March) and the early spring (March and April). It will be 

 seen that the investigation refers entirely to the winter months, 

 Mr. H. Parker gives, in the Ceylon Obxrvtr oi May 12, a 

 detailed account of the abnormal rainfall of 3172 inches in 

 twenty-four hours, e.Kperienced at Nedunkeni, in the Northern 

 Province of Ceylon, last December, and already briefly de- 

 scribed by a correspondent in these columns (p. 78). Nedun- 

 keni, eleven miles down the southern road to Mullaittivu, and 

 122 feet above sea-level, is a small village a little to the east of 

 the dividing ridge of North-Central Ceylon, and though itself in 

 the catchment area of the eastern Per Aru, which flows through 

 Tannir Murippu Tank, it is only a little to the south-west of the 

 point where three separate drainages meet.^ Forest, containing 

 a thick growth of high trees, extends over the neighbourhood, 

 and more especially for many miles from the south to the east. 

 For about three years a rain-gauge has been established in the 

 grounds of the dispensary in the village, and its records are 

 regularly transmitted to the Public Works Office, and are pub- 

 lished among the rainfall returns. Although the mean annual 

 rainfall at Nedunkeni is probably little more than 50 inches, the 

 fall for last December was 67*07 inches, and of this amount 

 3172 inches were measured at 9.30 a.m. on December 16 as the 

 rainfall of the preceding twenty-four hours. From an examin- 

 ation of the position of the rain-gauge, and the testimonies of 

 the observers, Mr. Parker concludes that most probably the 

 actual rainfall was in excess of the recorded amount. 



Weather influences on farm and garden crops are dis- 

 cussed in an interesting address by Mr. Edward Mawley, 

 published in the Quarterly Journal of the Royal Meteoro- 

 logical Society (April). After giving a short sketch of the 

 climate of the British Isles as a whole, Mr. Mawley con- 

 siders separately some of the effects produced on vegetation 

 in this country by varying temperatures, by scanty and heavy 

 rains, by sunshine and by wind ; and afterwards treats of the 

 leading farm and garden crops, and their special requirements 

 with regard to atmospheric conditions. The paper should be 

 of service in showing how intimate the connection is between 

 meteorology, agriculture and horticulture. 



Mr. T. Mellard Reade informs us that a very large 

 boulder of gypsum has been uncovered by the excavations in 

 the brickworks of Mr. Ed. Peters, Cooks Lane, Great Crosby, 

 near Liverpool. It is embedded in and completely surrounded 

 by a thick bed of brown boulder clay, the bottom of the 

 boulder being about 17 feet below the surface of the ground. 

 The boulder measures 11 feet by 6 feet by 6 feet extreme 

 dimensions, and weighs about 13 tons. "Small pieces of 

 gypsum and plates of selenite are," adds Mr. Reade, "not 

 uncommon in our boulder clays ; but this individual boulder 

 not only far surpasses in size any drift fragments of gypsum 

 hitherto found, but is actually the largest boulder of any sort 

 that I have seen taken out of the boulder clay, or recorded 

 from it in the neighbourhood of Liverpool." 



It is known that a function of two variables x and y may 

 have a maximum or minimum value along every straight line 

 passing through a certain point O without the function neces- 

 sarily being itself a maximum or minimum at that point. A 



NO. 1493, VOL. 58] 



simple proof that the same cannot be the case if the function is a 

 maximum at O, not only for ^W straight lines, but also for all 

 continuous lines through O, is given by Signor G. Vivanti in the 

 Atti de Lincei, yii. 8. 



The Royal Academy of Sciences of Naples has hitherto been 

 supposed to have originated about the year 1732, but from a 

 communication published in its Rendiconto, by Prof. Federico 

 Amodeo, we learn that the foundation of the Academy has been 

 traced back thirty-four years earlier. In 1698, under the 

 Viceroy, Luigi della Cerda, Duke of Medinacoeli, there was 

 founded, in Naples, a literary and scientific society called the 

 Palatine Academy ; this society appears to have been over- 

 looked by historians, owing to the fact that no published writings 

 of its members had come before their notice. Prof. Amodeo 

 has now succeeded in discovering a number of printed papers, 

 notably two scientific works of the mathematician Antonio 

 Monforte, affording abundant proof of the existence and activity 

 of this, the parent of the present Academy, which thus dates 

 from the year 1698. 



Prof. P. de Heen continues his researches on so-called 

 ' ' infra-electric " radiations in the current number of the Bulletin 

 de FAcademie royale de Belgique. The author is led to the 

 conclusions that every source of disturbance in the ether gives 

 rise not only to known radiations, but also to other rays vibrating 

 in a different manner. These rays have the same properties as 

 Rontgen rays in the matter of their action on dielectrics, 

 charged conductors and electric fields, and differ from them in 

 the matter of wave-length. They are absorbed so much more 

 readily than ordinary light waves, that any such rays which 

 emanate from the sun are completely sifted out by our 

 atmosphere. In accordance with M. Perrin's views, the dis- 

 charge of a conductor by these rays is chiefly due to their action 

 on the lines of force. Lastly, an electric field is found to 

 behave towards infra- electric rays as an opaque medium. 



An extremely simple commutator for converting an alter- 

 nating current into a direct one is investigated by Signor A. 

 Dina (of Zurich) in the Rendiconti del R. Istituto Lombardo, 

 xxxi 9. From the experiments of Prof. Gratz (of Munich) and 

 Herr Pollak (of Frankfort), it appears that an aluminium ele- 

 ment capable of evolving oxygen at the anode produces a re- 

 markable weakening of the current, and if the electromotive 

 force is less than 22 volts, practically no current flows ; but if 

 the pole in question is made the kathode, no perceptible change 

 in the current takes place, the electromotive force of the element 

 being less than i volt. Hence it is easy, by arranging such 

 elements in series, to obtain a combination which will only allow 

 currents to pass in one direction, and which will resist any re- 

 quired electromotive force in the opposite direction. From 

 experiments now described, the present writer concludes that 

 the action of the elements is similar to that of a condenser, the 

 aluminium becoming coated with a film of oxide which plays 

 the part of dielectric. Signor Dina has not succeeded so far in 

 putting the method to any practical use, though Herr Pollak 

 claims to have done so. 



A series of experiments on the action of opaque tubes on 

 Rontgen rays passing down them is described by Prof. Villari 

 {^Atti dei Lincei, vii. 8, and Rendiconto dell' Accademia di 

 Napoli, iv. 3, 4). In a series of previous experiments, Prof. 

 Villari found that in traversing a long tube opaque to them, these 

 rays lose a large part of their power of discharging an electrified 

 conductor at the end of the tube. This effect the author now 

 attributes to the action of the tube in cutting off lateral rays, 

 which, by their action on the surrounding air, would accelerate 

 the discharge. In the matter of photographic action. Prof. 

 Villari finds no difference between rays which have passed 



