396 
bulk of the tungsten. ore produced, occurs in various 
parts of the main mountain range in British Malaya, 
and in Pahang and Trengganu. Scheelite is mined in 
Perak and Selangor. 
Tue current issue (vol. xlvii., part 3) of the Records 
of the Geological Survey of India contains a review 
of the mineral production of India during 1915, com- 
piled by the Director of the Survey. The results may 
fairly be described as satisfactory, having regard to the 
conditions set up by the European War. The total value 
of the mineral products shows an increase of more 
than 700,000l, above that for 1914, some of this in- 
crease being undoubtedly due to the higher prices 
obtained for many of the products. The most impor- 
tant of these, however—coal—actually shows a de- 
crease in value of 126,o00l., although the output has 
risen from 16,464,000 tons to 17,104,000 tons, due to 
the lack of sufficient shipping to transport it, in conse- 
quence of which the price at the pits necessarily de- 
clined. The gold output is practically the same as in 
1914, but important increases in production are shown 
in tinstone, wolfram, and lead ore; these minerals 
come almost exclusively from Burma, where consider- 
able attention has recently been paid to the improve- 
ment of the means of transport and other facilities 
for the development of the mineral resources of the 
country. Petroleum is another mineral the produc- 
tion of which shows a very considerable increase. 
There has been a fall, on the other hand, in the out- 
put of manganese oré and iron ore; the reason for the 
former is to be found in the difficulty of . obtaining 
tonnage and in the high rates of freight. In this 
connection it is interesting to be able to chronicle the 
first attempt to utilise the ore within the peninsula, 
the Tata Company having put a furnace on to ferro- 
manganese, of which 2658 tons were produced. Atten- 
tion may also be directed to two pamphlets issued by 
the Department of Mines and Geology of the State 
of Mysore, one giving a brief account of the mineral 
resources of the State, which include, in addition to 
gold, ores of chromium, iron, and manganese, and 
the other a synopsis of the laws and regulations 
governing the issue of mineral licences; both these 
publications should prove of great interest to all who 
are, or are likely to be, interested in mining in this 
part of India. 
It is well known that the factors which determine 
the rate of evaporation of water from the earth’s sur- 
face are the depth of the surface of the water under- 
ground, the nature of the soil above this surface, the 
temperature and humidity of the air, and the speed 
with which it is moving. 
of the influence of each of these factors on the 
evaporation is known, but it has not been possible to 
determine the quantitative laws connecting them. The 
results of a research carried out by Messrs. F. S. 
Harris and J. S. Robinson at the Utah Agricultural 
Experimental Station during the past four years, and 
published in the United States Department of Agricul- 
ture Journal of Research for December 4, 1916, appear 
to justify the belief that before long these laws will have 
been discovered. By keeping the water level only a 
centimetre below the level of the surface of the sand 
or soil used, the authors have greatly reduced the 
effect of capillarity, and are able to give curves show- 
ing the effects of percentage of water in the soil, of 
the amount of dissolved salts in the water, of the size 
of grains and compactness of the soil, and of the speed, 
temperature, and humidity of the air on the rate of 
evaporation.” Copies of the paper may be obtained 
from the Government Printing Office, Washington, at 
1o cents a copy. 
NO. 2464, VOL. 98] 
To a great extent the nature. 
NATURE 
[January 18, 1917, 
WuiLE the name of Pappus of Alexandria iis asso- 
ciated in the minds of modern mathematicians with 
Guldin in the theorem relating to ghe volume and area 
of the surface traced out by a moving closed curve, 
practically nothing is known of the life of. the 
geometer himself. An introductory paper on Pappus 
is now given by Dr. J. H. Weaver in the December 
Bulletin of the American Mathematical Society. Of 
the eight works attributed to him, the only one extant 
even.in part is the ‘‘ Collectio,’ which is a summary in 
eight books of the works of preceding Greek mathe- 
maticians, of which Dr. Weaver gives a_ general 
account. Of this an edition was published by Hultsch, 
of Berlin, in 1876-78." Reference is also made to 
Sir T. J. Heath’s article on Pappus in the “ Encyclo- 
pedia Britannica,” eleventh edition. 
An outline of the mathematical course of an Italian — 
technical school is given by Prof. Virgil Snyder in 
the Bulletin of the American Mathematical Society 
(xxiii., 3). The account refers to the Reale Istituto 
Tecnico Superiore of Milan, where, as elsewhere in 
Italy, the course extends over five years, and includes 
a two-year course in mathematics, physics, and chem- 
istry, as also in Italian and two other languages. 
Candidates for admission are required to be familiar 
with plane and solid geometry, plane trigonometry, 
algebra including determinants, theory of equations, 
graphical processes, and elementary projective geo- 
metry. Differential calculus is only commenced as 2 
portion of a heavy course in the first term, and integra- 
tion in the second term is taken by the students, to- 
gether with an extensive discussion of analytical solid 
geometry. 
WHEN all the roots of an algebraic equation are _ 
complex with modulus unity, it is fairly evident that 
the equation must be reciprocal. Writing in the 
Tohoku Mathematical Journal (x., 3), Mr. A. Kempner, 
of Urbana, U.S.A., gives certain extensions of previous 
work relating to equations having roots of this 
special form, and in particular proposes a simple proof 
of the theorem that if one such pair of roots exists 
the equation must be reciprocal provided that it is 
irreducible in the domain of rationality formed by the 
coefficients. The journal contains the usual summary 
of new books and contents of mathematical periodicals, 
of which the latter form a very useful reference cata- 
logue of current mathematical literature. We could 
wish, however, that this portion, appealing as it does 
to readers of all nations, did not contain so much 
matter in Japanese characters, or that a translation 
were given in English or French. 
We have received an official publication of the 
Government of South Australia entitled ‘‘ An Investi- 
gation into the Prospects of Establishing a Paper- 
making Industry in South Australia,” by Mr. W. A. 
Hargreaves, being Bulletin No. 1 of the Department 
of Chemistry, of which the author is director, and 
“issued under the authority of the Hon. R. P. Blun- 
dell, Minister of Industry.”” Of indigenous raw mate- 
rials for paper-making Australia presents a conspicu- 
ous dearth, and Mr. Hargreaves’s conclusion from his — 
exhaustive investigations is that the only immediate 
industrial proposition is the utilisation of cereal straws ; 
lime-boiled for ‘‘strawbdards”’ and caustic-boiled for 
‘cellulose’? papers—i.e. for printings and writings; 
in the latter case the paper-furnish requiring from 
30-40 per cent. of bleached wood cellulose, which 
means an imported raw material. The cost of pro- 
duction of the bleached straw pulp from the hypo- 
thetical works’ cost-sheets is 71.-81. per ton; the pro- 
cess described and ‘costed’? is based on the caustic- 
soda boil, with So per cent. recovery, and the assump- 
| tion that ‘the losses of caustic soda are made up 
