JUNE 12, 1902] 
death in September last year brought to an end a career of great 
promise. Dr. von Krafft had already earned his reputation as 
an able geologist while occupied on the Geological Survey of 
Austria, previous to joining the staff of the Geological Survey of 
India in 1899. In that year, and subsequently, he accom- 
plished brilliant work in the Himalayas, and showed himself 
to be exceptionally well qualified for the difficult tasks allotted 
to him. His early death at the age of thirty has caused the 
profoundest regret in geological circles. 
THE Royal Meteorological Institute of the Netherlands has 
issued its fifty-first year-book, containing observations for 
1899. This is the first volume of a new series, in which the 
results are presented in the form adopted by the International 
Meteorological Committee, and is a great improvement upon the 
form in which the observations have hitherto been published. 
Mr. MAXWELL Hatt has published a paper (No. 275) on 
¢he temperatures of Kingston, Jamaica, for the years 1881-98. 
The annual mean is 78°'8, highest maximum 96°'7, in August 
¥891, lowest minimum 56°'7, in December 1887. The lowest 
mean maxima occurred in 1884 and 1893, near the times of the 
sun-spot maxima, and the highest in 1889, at the time of the 
sun-spot minimum, and these effects are reproduced in the mean 
temperature column, A table is also given showing the rainfall 
in Jamaica from about ninety stations between 1866 and 1900; 
the greatest fall was 90°6 inches, in 1886, and the least 45°2 
inches, in 1872. 
Mr. R. Sworpy sends us a few particulars of a somewhat 
temarkable shower of hailstones which fell in Cheltenham and 
the surrounding district on June 7, shortly before noon. At 
first the hailstones were more or less round and like small 
erystallised raspberries ; but during the latter and main part of 
the shower they were in the form of wedges or small cones, 
somewhat varied in shape. Many of these hailstones were 
about three-quarters of an inch in height and measured about 
half an inch across. Mr. Swordy suggests that these 
were only conic sectional parts of what had been much larger 
hailstones. To test this view he put some selected ice cones 
in a circle and added two more layers upon the first 
circle and a key wedge or cone at the top. By this arrange- 
ment he obtained half an ice-ball, consisting of fifteen sections. 
The hailstones when first formed may therefore have been about 
the size of ‘‘ ping-pong” balls, and about an inch and a half 
Or two inches in diameter. Mr. Swordy adds :—“ The grain of 
the ice in these sections (which, I presume, had formed the 
balls originally) radiated from the centre towards the outside, 
and were hardest on what I suppose had been the outside ; so 
that it is probable that the freezing, which must have com- 
menced from the outside of each water globule and progressed 
towards the centre, thus bringing pressure to bear on the centre 
of each ball, may have caused them to explode and form the 
cones mentioned.” 
In a note on ‘‘ mathematical meteorology,” Prof. Luigi de 
Marchi contributes to the Lombardy Rezdiconti an investiga- 
tion of the equations of motion of air-currents due to variations 
of temperature, with especial reference to the effect of solar 
eclipses. The action of an eclipse, it is pointed out, is to pro- 
duce what Mr. Helm Clayton has called a cyclone with a cold 
centre. 
WE have received from Messrs. A. E. Staley and Co. a copy 
of the fourth edition of ‘‘ Manipulation of the Microscope,” by 
the well-known optician, Mr. Edward Bausch. It is a small 
illustrated handbook specially designed to meet the wants of 
beginners, and the sections dealing with the use and care of the 
microscope have been reprinted for distribution in class-rooms 
and laboratories. 
NO. 1702, VOL. 66] 
NATURE 
159 
————— 
No. 182 of the Bwd/eten of the French Physical Sociely con- 
tains a note on a new ‘‘electric valve” for transforming re- 
ciprocating currents into direct currents, due to M. Nodon, 
This ‘‘ valve” is based on the property, discovered by Buff in 
1857, that an aluminium electrode plunged in an electrolyte 
offers a great resistance to the passage of a current in which it 
is the anode. The efficiency of M. Nodon’s apparatus, as 
measured by a wattmeter, reaches 75 to 80 per cent. 
AN oxy-acetylene blowpipe is described by M. Fouché in the 
Bulletin of the French Physical, Society, No. 182. The flame 
is formed by the combustion of a mixture of one, part of acetyl- 
ene to 1°8 of oxygen, and in order thatthe explosion may not 
travel back into the blowpipe a jet velocity is required. due to 
the pressure of a water column 4 metres in height. The 
flame melts most metals readily; it will solder iron and steel, 
and even silica and lime are melted by it. With a reduction of 
the proportion of oxygen the flame becomes luminous, and on 
falling on lime the free carbon goes to form carbide of lime. 
IN the Rendiconto of the Naples Academy, viii. 2. Signor E. 
Cesiro deals with certain limitations of constants in the analy- 
tical theory of heat. His investigation refers to the. property 
that in order to satisfy the partial differential equation Vz + hu 
throughout a given region S, subject to the boundary condition 
du/dn+hu=o at the surface of S, the constant 4 must fora given 
value of # belong to a discrete series of positive quantities, 
which all increase with %. The author also discusses the 
question of the expansion of the temperature due to an initial 
distribution in a series of functions of the form considered. 
Pror. LE NEVE Foster has given a useful practical address 
on the study of mineral veins (Zazs. Royal Geol. Soc. Cornwall, 
vol. xii. part vii.). Mr. J. B. Hill, in dealing with the relation of 
the plutonic and other intrusive rocks in west Cornwall to the 
mineral ores, expresses the opinion that the intrusion of the 
greenstones was separated by no great interval from the irruption 
of the granites, and that the copper and tin lodes originated in 
pre-Triassic times and followed. closely on the cooling of the 
intrusive rocks. 
A Bulletin issued by the U.S. Department of Agriculture 
concerning Kentucky bluegrass seed affords a striking instance 
of the amount of trouble which Americans will take to improve 
a product of comparatively trifling value. The cultivation of 
bluegrass is confined to a small area in the States of Kentucky, 
Missouri and Iowa. The harvesting is performed entirely or 
partially by hand, as automatic strippers do not seem to find 
favour. 
Tue latest number of the /ouwrna/ of the Royal Horticul- 
tural Society completes the twenty-sixth volume. Two articles 
of an economic nature suggest to fruit-growers the possibility of 
making a profit out of surplus fruit. Mr. Austin claims to have 
devised a practical and efficient method of putting up fruit in 
bottles, while Mr. Udale brings forward the results obtained 
by drying fruits and vegetables in special evaporators. There 
is no apparent reason why the British farmer should not take up 
these industries and possibly oust imported articles. Captain 
Hurst having made a study of the characters of certain orchid 
hybrids, finds that they confirm the laws evolved by Mendel 
as the outcome of his experiments in hybridisation. 
THE Report of the Zoological Society of Philadelphia for 
gor shows that the institution is in a flourishing condition. 
It is satisfactory to learn that the educational value of the 
menagerie is fully realised by the public schools of the city, 
which are in the habit of sending parties of scholars accom - 
panied by teachers. 
