Dec. 2, 1869 | 
NATURE 
145 
changes which have been observed, is so great as to suggest 
a strong probability that this nebula is much mearer to us 
than the stars which are seen along with it. It may be also 
noticed that M. Le Sueur saw nothing to make him believe in 
any development of stars in addition to those seen by Sir J. F. 
W. Herschel.” The Council of the Society believes that an 
attempt to encourage and aid spectroscopic researches is an 
object in full unison with the highest purpose of the Royal 
Society’s existence; and they have, therefore, after most careful 
deliberation, resolyed to act on this conviction. A telescope of 
the highest power that is conveniently available for spectroscopy 
and its kindred inquiries is being constructed, and will be en- 
trusted to such persons as, in their opinion, are the most likely 
to use it to the best advantage for the extension of this branch of 
science; and, in the first instance, there can be but one opinion that 
the person so selected should be Mr. Huggins. ThePresidentsaid: 
“The execution of this project was much facilitated by the receipt 
of £1,300 from a bequest made to the Society by the late Mr. 
Oliveira; and in the beginning of the year proposals were received 
from the chief opticians of the time, of which that of Mr. Grubb 
was accepted last April. The conditions proposed were, that 
the object-glass of the telescope should be of 15-inches aperture, 
and not more than 15-feet focus, that the arrangements of its equa- 
torial should be such that it could be easily worked by the observer 
without an assistant, and that the readings of its circles could be 
made without leaving the floor of the observatory. Mr. Grubb was 
fortunate enough to secure two discs which had been exhibited 
by Messrs. Chance at the French Exhibition. They are of first- 
rate transparency, and as the construction which has been 
adopted admits of the lenses being cemented, this object-glass 
will transmit an unusual portion of light. The respective indices 
of the glasses were determined by making facets on their edges 
at an angle of 60’, and observing spectral lines through the 
prisms thus formed with a spectroscope of such magnitude as to 
admit of their being placed on its table. The distinctness with 
which even faint lines are seen through 12 inches of the glass is a 
most satisfactory proof of its purity and clearness. From these 
Professor Stokes computed the curves for the lenses, and his 
numbers were almost identical with those which Mr. Grubb had 
obtained. I may mention that some fears had been entertained 
that the equality of curvature in the adjacent surfaces might ca// 
up a ghost, if the lenses were used uncemented, and that this has 
been tried and no such effect was visible. Subsequently a rather 
novel addition has been made, bearing upon the radiation of heat 
from the stars. An object-glass intercepts so much of the heat- 
rays that, to economise the infinitesimal effect which is expected, 
a metallic mirror is more promising. The equatorial is, therefore, 
at the suggestion of Mr. De la Rue, provided with the means of 
changing the 15-inch achromatic for an 18-inch reflector; and 
this has been accomplished by means notable for their facility and 
their safety. The instrument will be ready for trial in December 
of the present year.” The rest of the address referred to the 
recent dredging expedition. The President then proceeded to 
the award of the Medals. The Copley Medal was awarded to 
M. Victor Regnault for the second volume of his “ Relation des 
Expériences pour determiner les lois et les données physiques 
nécessaries au calcul des Machines a Feu,” including his elaborate 
investigations on the Specific Heat of Gases and Vapours, and 
various papers on the Elastic Force of Vapours. The President 
remarked that the name of M. Victor Regnault had been 
associated for the last quarter of a century with the most refined 
and delicate experimental inquiries connected with the measure- 
ment of heat. The amount of labour involved in his researches 
upon the specific heat of simple and compound bodies, upon the 
dilatation of gases and vapours, upon the comparison of the air- 
thermometer with the mercurial thermometer, upon the elastic 
force of aqueous vapour, upon the determination of the density 
of gases, and upon hygrometry, must excite the astonishment 
of all who could estimate the difficulty of the problems 
attacked, the precision of the results attained, and the 
fundamental character of the data which he had determined. 
The Council has awarded a Royal Medal to Sir Thomas 
Maclear, Astronomer Royal at the Cape of Good Hope, for his 
measurement there of an arc of the meridian. The President re- 
minded his audience that our sole knowledge of the figure of the 
southern hemisphere rested on the arc of the meridian measured 
by La Caille, and now remeasured and extended by Maclear. 
The original measurement, notwithstanding the well-known 
ability of the great astronomer under whose superintendence 
it was executed, had not commanded confidence, Maclear’s 
arc has an amplitude nearly four times as great as that of La 
Caille, and is, on this account, as well as on account of the 
greater accuracy in detail, far more deserving of confidence. 
The degree which is derived from it is 1,133 feet shorter than 
that of La Caille ; and as La Caille’s is 1,051 longer than that 
given by the spheroid, which, according to Airy, represents the 
average of northern arcs, it is evidently a near approximation 
to the truth. This is even more distinctly shown by the close 
agreement of the latitudes computed from the geodetic 
measurements with those given by the sector—that of the north 
extremity being 0’*4 in defect, that of the south extremity 0”°5 
in excess.—A Royal Medal has been awarded to Dr. Augustus 
Matthiessen, F.R.S., for his researches on the electrical and 
other physical properties of metals and their alloys. The 
President remarked that these researches embraced the de- 
terminations of the specific gravities, the expansion due to heat, 
the thermo-electric properties, the electric conducting-power, 
and the effects of temperature upon the electric conducting- 
power. Dr. Matthiessen’s investigation of the electric con- 
ducting-power of commercial copper had resulted in very great 
improvement of the conducting.power of the copper wire used 
in submarine telegraphy. Closely connected with this branch 
of his researches were the investigations which Dr. Matthiessen 
carried out for the Electrical Standard Committee of the British 
Association, of which he was one of the most active members. 
The resistance-coils issued by that Committee, which had been 
very generally adopted as standard instruments, were all con- 
structed of an alloy of platinum and tin, which, after a long 
series of experiments, Dr. Matthiessen recommended as specially 
fitted for that purpose. Under the auspices of the British 
Association, Dr. Matthiessen undertook, a few years ago, the 
investigation of the chemical constitution of cast-iron, and of 
the influence exerted upon the physical properties of that metal 
by the several other elements which generally occur in associa- 
tion with it. He had lately elaborated a method of producing 
pure iron, which promised to be fruitful in interesting and 
important results in the hands of himself and the other 
chemists with whom he has been associated in this inquiry. 
Dr. Matthiessen’s researches published in the PAzlosophical 
Transactions, on the action of oxidising agents upon organic 
bases and on the chemical constitution of narcotics (the 
latter investigation having been conducted in conjunction 
with Professor G. C, Foster), furnished proofs of the suc- 
cess of his labours in organic chemistry. His researches 
were distinguished as well for their diversity as for their 
uniformly complete and trustworthy character. — The fol- 
lowing officers are elected for the ensuing year :—President: Sir 
Edward Sabine, L.L.D.; Treasurer: W. Allen Miller, M.D.,, 
EE. Dt Secretaries: W. Sharpey, M.D., LL.D.; and G. 
Gabriel Stokes, LL.D. Foreign Secretary: Professor W. Hal- 
lows Miller, LL.D. The other members of the Council are: 
Frederick Currie, M.A.; Warren De la Rue, Ph. D.; Sir P. de 
M. Grey Egerton, Bart.; Professor W. H. Flower, F.R.C.S. 
Eng.; William Huggins; J. Gwyn Jeffreys; John Marshall, 
F.R.C.S. Eng.; Augustus Matthiessen, Ph. D.; Captain Henry 
Richards, R.N.; the Marquis of Salisbury, M.A.; C. W. Sie- 
mens ; John Simon, F.R.C.S.; Archibald Smith, M.A.; Pro- 
fessor H. I. Stephen Smith, M.A.; Professor John Tyndall, 
LL.D.; and Professor Alexander W. Williamson, Ph.D. 
Royal Astronomical Society, November 12.—First Meeting 
of Session, Mr. Warren De la Rue, F.R.S., vice-president, in 
the chair. The Chairman opened the meeting by referring to 
the illness of Admiral Manners, the president of the society, an 
announcement which was heard by all present with much regret. 
The minutes of the last meeting having been read and confirmed, 
and upwards of 100 presents announced, Mr. Carrington read 
a paper descriptive of his observatory near Farnham, Surrey, and 
of a variety of ingenious contrivances for securing its efficiency, 
and especially the correct measurement of time. Mr. Carrington 
intends observing with an alt-azimuth, which he has designed to 
ensure the comfort and consequent accuracy of the observer. 
The telescope-tube rotates freely on its axis, which is always 
horizontal; it carries the vertical circle, and in front of the 
object glass a right-angled prism, the front face of which may be 
directed on any object by the axil rotation of the tube of the 
telescope. —The Astronomer-Royal was then invited by the Chair- 
man to describe his recent invention of a method of correcting 
the chromatic dispersion of the atmosphere. He described the 
various contrivances by which that object might be secured. 
