516 
course of his presidential address, points out how entomologists 
may assist in elucidating many problems of biology. He rightly 
remarks that, ‘* Without entering very far into the philosophical 
phase of his subject, every practical entomologist has it in his 
power to contribute something towards solving one or the other 
of the problems connected with variation, heredity, and the 
general laws operating in the production of species. He is 
already expert at rearing insects from the egg ; let him continue | 
to do this, but let him conduct his rearing operations on experi- 
mental lines. . . . A useful course of experimental work would be 
to endeavour to develop some particular varietal tendency ex- 
hibited by a species.” 
THE spring announcements of the Cambridge University 
Press include :-—The Collected Mathematical Papers of the late 
NATURE 
i 
Arthur Cayley, F.R.S., to be completed in thirteen volumes, | 
vol. xii. ; The Scientific Papers of John Couch Adams, F.R.S., 
vol. ii., edited by Dr. W. G. Adams and R. A. Sampson; The 
Foundations of Geometry, by the Ilon. B. Russell ; A Treatise 
on Abel’s Theorem, by H. F. Baker ; The Theory of Groups of 
a Finite Order, by W. Burnside, F.R.S.; A Treatise on Uni- 
versal Algebra, with some applications, by A. N. Whitehead. 
Vol. i. contains the General Principles of Algebraic Symbolism : 
The Algebra of Symbolic Logic : The Calculus of Extension 
(z.e. the Algebra of Graffmann’s Ausdehnungslehre), with appli- 
cations to Projective Geometry, to Non-Euclidean Geometry, 
and to Mathematical Physics; A Treatise on Octonions: a 
McAulay; A Treatise on Spherical Astronomy, by Prof. Sir 
Robert S. Ball, F.R.S. ; A Treatise on Geometrical Optics, by 
R. A. Herman ; An Elementary Course of Infinitesimal Calculus, 
for the use of Students of Physics and Engineering, by Prof. 
Horace Lamb, F.R S. ; Theoretical Mechanics : an introductory 
Treatise on the Principles of Dynamics, with numerous appli- 
cations and examples, by A. E. H. Love, F.R.S. ; The Works 
of Archimedes, edited in modern notation, with introductory | i y : 
| Prof. W. J. Hussey contributes measures of eighty different 
chapters, by Dr. T. L Heath; Handbook to the Geology of 
Cambridgeshire, by F. R. Cowper Reed. Cambridge Natural 
Science Manuals.—(Biological Series) Fossil Plants: a Manual 
for Students of Botany and Geology, by A. C. Seward ; The 
Vertebrate Skeleton, by S. H. Reynolds ; Vertebrate Palon- 
‘tology, by A. S. Woodward ; (Physical Series) Electricity and 
Magnetism, by R. T. Glazebrook, F.R.S.; Sound, by J. W. 
Capstick ; (Cambridge Geographical Series) A History of Ancient 
Geography, by the Rev. H. F. Tozer, with ten maps. 
THE additions to the Zoological Society’s Gardens during the 
past week include a Chacma Baboon (Cynocephalus porcarius, 3 ), 
a Levaillant’s Cynictis (Cyzctés penzce/lata), a Black-backed 
Jackal (Cavs mesomelas) from South Africa, presented by Mr. 
J. E. Matcham ; a Cheetah (Cyzalurus jubatus) from Africa, 
presented by Colonel W. II. Wylde ; a White-bellied Pangolin 
(Manis tricuspis) from Lagos, presented by Mr. F. W. Marshall; 
an Alexandrine Parrakeet (Palzornis alexandri, 8) from India, 
presented by Mrs. Randall ; a Severe Macaw (dra severa) from 
South America, presented by Mrs. J. Keser; three Indian 
Pigmy Geese (Weltopus coromandelianus, 6 § 2) from India. 
presented by Mr. Frank Finn; a Tesselated Snake (77ofido- 
notus tessedatus) from South Europe, presented by Mr. W. R. 
Temple ; a Natal Python (Python sede, var ) from South Africa, 
presented by Mr. Luscombe Searelle ; three Purplish Death- 
Adders (Pseudechis porphyriacus), a Shielded Death-Adder 
(Notechts scutatus), three Australian Banded Snakes (Déemenia 
nuchalis), an Occipital Elaps (rina occepitalzs) from Aus- 
tralia, deposited ; a Maximilian’s Aracari (Pleroglossus wed?) 
from Brazil; two Rosy-faced Love-Birds (Agafornzs rosetcollis) 
from South Africa, purchased ; two Collared Fruit Bats (Cyzo- 
nycterts collaris), born in the Gardens. 
NO. 1431, VOL. 55] 
| of these new canals, remarking that he never saw any of the 
| the south polar snow, and on the same date the north pole was 
development of Clifford’s Bi-Quaternions, by Prof. Alexander 
| Ahademze der Wessenschaft. 
[ APRIL 1, 1897 
OUR ASTRONOMICAL COLUMN. 
Tue PLANer MARs.—Prof. Schiaparelli has just published 
an account of his observations of Mars made during the years 
1883-84. These observations are contained in the publication 
of the Aeale Accademia det Lincet, 1895-96, and are accom- 
panied by a new chart of the surface-markings and eight 
diagrams of the planet’s disc. Of the thirty-one canals seen 
to develop in 1881 and 1882, only eighteen have been observed 
again at this opposition, while seven new ones have been noted. 
In the polar gap a large dark rift was seen, apparently separat- 
ing the snow into two unequal portions. An examination of 
the chart with that published by Lowell will be found to give 
many interesting points of difference. In the March number of 
the Bulletin de la Soctété Astronomigue de France there will — 
be found a brief account of these observations, with reproduc- 
tions of the plates in Schiaparelli’s original memoir. There are © 
added a series of drawings of the planet observations, made from 
the Observatory of Juvisy, at the opposition in December last. 
Some interesting observations, made of Mars last year, are con- 
tributed to the current numberof the Astronomeschen Nachrichten 
(No. 3411). The observer, Herr Leo Brenner, saw altogether 126 
canals, 31 of which were new, while 13 and $2 were Lowell’s and 
Schiaparelli’s respectively. He gives, in a table, the positions 
canals doubled. Five new seas were seen by him at positions 
B=162° and +32°, C=261° and +36°, D=270° and +48’, 
E=201° and +27°, 4=215° and +3°. The sea E had been pre- 
viously seen by Antoniadi, who thought that it represented a 
doubling of Trivium. Propontis was seen doubled, the old one 
lying to the westward. On September § the last was seen of 
distinctly observed. Nilosyrtis was bridged over as shown in 
Schiaparellis map of the year 1882, but further to the south 
than is shown there. Several other points of interest were 
noted. A full account of these will be published in the Aazs, 
In the same number of the stv, Vachr., mentioned above, 
M.V. Cerulli gives a brief account of his observations on Mars, 
made between October 1896 and January of this year. 
DouBLE-STAR MEASURES.—The Astronomical Fournal (No. 
397) gives the measures of several observers of double-stars. 
eee eee 
doubles made with the 12-inch and 36-inch of the Lick Observa- 
tory. The Morrison Observatory adds several more, measured 
| by Mr. Henry S. Pritchett with the 12-inch of that observatory. 
Mr. W. S. Eichelberger, of the Wesleyan University Observa- 
tory, Middletown, also publishes afew measures, but does not 
state the size of the instrument employed. Several bright 
objects among the southern stars, which have hitherto been sup- 
posed to be single, have now been proved to be double, accord- 
ing to Prof. T. J. J. See (Ast. Nach., No. 3312). Further, 
several wide pairs have been resolved into triple systems of — 
high interest. Three special cases of the former are mentioned, — 
and as they seem likely to be of interest to other observers, we 
give the following data :— 
wv Velorum, discovered 1897 January 31. | 
a = gh. 26m. 46°6s. — 40° 1’ 50""5 (I1g00°0 
1897°084. Pos. angle 258°°8. Dist. 0”*54. 
} 
Mag. 5 and 5'1. Both yellow. 
p Velorum, discovered 1897 January 10. 
a =Toh. 33m. 65s. O= — 47° 42’ 3’°9. 
1897°065. Pos. angle 268°-9. Dist. 07°47. 
Mag. 4°6 and 5°2. Both yellow. 
A Lup, discovered 1897 February rf. 
@ Thieme es. 0 = — Ade5s aiecss 
1897'085. Pos. angle 178°°6. Dist. 0”*30. 
Mag. 4°9 and 5:2, Both yellow. 
BELGIUM OBSERVATORY ANNUAL.—The director of the 
Royal Belgium Observatory brings together in the annual for 
this year (the sixty-fourth year) a mass of useful information 
which will be serviceable to meteorologists as well as astro- 
nomers. In addition to the usual solar and planetary eph- 
emerides, occultations, &c., Prof. F. Folie has written some short 
chapters on the following points :—A reaction in astronomy, 
accurate history of the discovery of diurnal nutation, ex- 
planations of the systematic differences between the Greenwich, 
