Nov. 18, 1869] 
NATURE 
87 
contain the titles of all written or oral communications, and 
the names of their authors. A small space in each number 
will be used to announce the recent correspondence, and 
donations to the library and museum, and to state deficiencies 
existing in the collections, and the methods in which its 
friends may best aid in rendering them more complete. There 
will also be inserted a list of some of the duplicate volumes, 
pamphlets, newspapers, &c., in the library, which will be offered 
for exchange or sale. It is expected that the variety and interest- 
ing character of the communications this volume will contain, 
will make it a favourite with the public, while its low price will 
bring it within the means of all. The Bulletin can be obtained 
of Messrs. Triibner & Co. 
A REPORT on excisions of the head of the femur for gunshot 
injury, by Mr. G. A. Otis, assistant-surgeon United States army, 
is the latest of a series of elaborate reports on important medi- 
cal and surgical questions, published by the Surgeon-General of 
the War Department at Washington. The liberality of the 
Government of the United States in matters of science is, or at 
least should be, well known; and the handsome form in which 
these volumes, illustrated by numerous woodcuts, lithographs, 
and chromolithographs, are issued, deserves notice at our hands, 
although questions of practical surgery lie outside the province 
of NATURE as understood by us. In the volume we have, first, 
an apparently exhaustive historical survey of the operation of 
excision at the hip, and then the detailed records of the operation 
during the late civil war, these records being illustrated by figures 
of the pathological specimens and lithographs of individuals 
successfully operated on: finally, the records of temporisation 
are discussed, and the results compared with excision and ampu- 
tation, Whether the surgical reader will endorse Mr. Otis’ 
conclusions or not, they will, we are sure, agree that his report 
is in every way creditable to American military medical science. 
PROFESSOR GRANT, the director of the Observatory in 
the University of Glasgow, has printed two letters, which he 
addressed to M. Leverrier, on the authenticity of the documents 
respecting Newton, communicated to the Academy of Sciences 
by M.Chasles. These letters, which are now more than two years 
old, have since the exposure of the Newton-Pascal forgeries, 
become specially interesting. They must be read in connection 
with M. Leverrier’s more recently indited brochure. 
THE sixty-eighth annual election of office-bearers of the Philoso- 
phical Society of Glasgow was arranged to take place last night 
(Wednesday), Professor Grant retires from the office of senior 
vice-president, and the Rev. H. W. Crosskey from that of librarian. 
The following members of council retire by rotation: Mr. 
Ramsay, of Kildalton, Professor W. J. Macquorn Rankine, Sir 
William Thomson, and Mr. William Ramsay. 
A LETTER from Gross-Gerau in the Cologne Gazette, dated last 
Saturday, quoted in the fal Mall Gazette, says that on the 
previous Wednesday a gentle rumbling was observed twenty-five 
times, but only one shock ; on Thursday there were twenty-three 
rumblings, and a shock about midnight, On Friday there were 
six violent shocks resembling those of the 30th ult., and in the 
night, up to 7 a.m., there were nine more shocks, accompanied 
by frequent thunder. During the morning of Saturday there was 
again a calm, but in the afternoon two violent shocks were felt, 
the last of which occurred very suddenly at 4.32. It is a very 
remarkable fact that these shocks have entirely altered in character 
from the earlier ones, being announced by a single thunderclap 
similar to the noise of a cannon shot fired at a distance of some 
miles, but much stronger. Their direction, too, is vertical 
instead of horizontal as before. The total number of shocks felt 
at Gross Gerau during the last three weeks is between seven and 
eight hundred. Most of the clocks and watches in the place 
have stopped, and the houses have all been more or less damaged, 
even those which are built of stone. The earthquake has also 
destroyed sixty-one chimneys. What if the volcanic region of the 
Eifel should burst open with its old activities, and the beautiful 
Laacher See and Pulyermaar, and the Mosenberg among others 
should favour us with phenomena which formerly one has gone 
at least as far as Vesuvius to see ! 
THE Royal Society has just issued Part I. of their rs9th 
volume, the bulk of which is in very fair ratio to the importance 
of its contents. We have first a paper on Solar Physics, by 
Messrs. De La Rue, Stewart and Loewy, containing a first in- 
stalment of the measurements made with a view of making the 
solar photographs taken at Kew the basis of a new determina- 
tion of the sun’s astronomical elements: the privately-printed 
papers, with which all astronomers are familiar, are acknowledged 
to have been preliminary. The great Melbourne telescope is 
exhaustively described by Dr. Robinson and Mr. Grubb, and 
the description is accompanied by admirable and numerous 
plates, so that all may gain a very ample notion of the grand in- 
strument from which so much may be anticipated. Terrestrial 
Magnetism is the subject of two papers, one by the Astronomer 
Royal, the other by Mr. Chambers ; while prolific Prof. Cayley 
has three mathematical memoirs—one on Skew Surfaces otherwise 
Scrolls, another on the Theory of Reciprocal Surfaces, and the 
last on Cubic Surfaces. The Formation and Early Growth of 
the Bones of the Human Face, by Mr. Callender; the Osteology 
of the Solitaire or Didine Bird of the Island of Rodriguez, 
illustrated by ten exquisite plates by Ford, by Messrs. A. and E. 
Newton; the Developments of the Semilunar Valves of the 
Aorta and Pulmonary Artery of the Heart of the Chick by 
Dr. Tonge, are the papers which appeal to biologists; and 
Mr. Gore’s paper on Hydrofluoric Acid, and one by Mr. Lockyer 
on Spectroscopic Observations of the Sun, are the other memoirs 
included in the volume. 
WE have to record the death of an astronomer of European 
reputation, Mr. W. F. Donkin, F.R.S., Savilian Professor of 
Astronomy at Oxford, and Honorary Fellow of University College. 
ASTRONOMY 
Correction of Atmospheric Chromatic Dispersion 
Tue Astronomer Royal, in his last communication to the Royal 
Astronomical Society on the Transits of Venus, adverted to the 
injurious effect on the observations, which might possibly arise 
from the chromatic dispersion produced by the atmosphere, and 
suggested that probably an efficient corrective might be found, 
in the application of a glass prism of small refracting angle in 
the eye-piece of the telescope. In a subsequent communica- 
tion on the same subject, after stating the optical theory, 
Mr. Airy continues :—Suppese, then, that we have a series of 
flint prisms ground to the angles 2°, 4°, 6°, 8°, 12°, 16°. And 
suppose that we use a telescope with power 120 or with power 
240. Then the following table, showing the zenith distance at 
which the atmospheric dispersion is corrected, is easily computed; 
the refraction being calculated by the formula just given, and the 
zenith-distance corresponding to the refraction being taken from 
a common table of refractions :— 
Telescopic power 120. Telescopic Power 240. 
Angle of | Atmospheric Zenith Atmospheric Zenith 
Flint Prism. Refraction. Distance. Refraction. Distance. 
° Gon Dt 
2 18 61 58 °'9 43 7 
4 36 75 16 18 61 58 
6 54 80 15 27 79 32 
8 72 82 52 36 75 16 
12 10'8 85 34 54 80 15 
16 14°4 87 3 72 82 52 
For view with the naked eye it would be necessary to use a 
prism (of appropriate small angle) with its edge downwards ; 
but, for view with an inverting telescope, the edge of its appro- 
priate prism must be upwards. : 
The object I proposed is completely attained. It is made 
possible, by this construction, to examine a celestial body with 
delicacy and accuracy, under circumstances which would, 
