stances, which are also represented in tea to a much smaller extent, and which readily pass by chemical decomposition into the form of fat. Beer, wine, and spirits are all fattening, partly in consequence of their saccharine and starchy constituents, and partly from their tendency to hinder excretion of waste products of food, and, when acting on any

VOLCANIC DUST IN CONNECTION
WITH THE LATE REMARKABLE
SUNSETS.*

THE

SCIENTIFIC SOCIETIES.

MICROSCOPICAL SOCIETY OF

LIVERPOOL.

HE fifth ordinary meeting was held at the Royal Institution, Colquitt-street, on Friday, the 2nd of May, 1884, Chas. Botterill, President, in the chair, when a lecture was delivered entitled Larval Forms of the Echinodermata," illustrated by the oxy-hydrogen lantern, by Professor Herd

man, D.Sc.

but a languid frame, to hurry and to slur that T
methodical oxidation by the blood on which the
maintenance of sound tissue depends. General
opinion, we are sure, will bear us out in saying that
when the solids consumed are moderate in amount
and digestible, and when the fluid is merely fluid,
not fatty or amyloid in its composition, and not
The lecturer commenced by referring to the
stimulant, free drinking will not influence obesity; somewhat isolated systematic position, and the wide
We can call to mind heavy drinkers of water and distribution in space and time of the Echinoder-
regular consumers of tea, moderate in diet other-mata, and to the doubts which still exist as to their
wise, whose habits engendered not the slightest relationship with other groups of the Invertebrata.
tendency to corpulence. We should without He then, after briefly describing some of the more
hesitation recommend their practice to the stout, important anatomical peculiarities of the echino-
and should rely for the reduction of their bulk not derm, proceeded to discuss the embryology of cer-
on any further alteration of their diet, which might tain members of the five classes living in the seas of
easily be carried so far as to starve their more im-
the present day. Commencing with the Holothu-
portant tissues, but on the maintenance of regular roidea (or sea cucumbers), the development of
and sufficient physical exercise.-Lancet.
Holothuria tubulosa and of Cucumaria doliolum
was traced from the fertilisation of the ovum to the
Auricularia stage according to the observations of
Selenka. The characters of the Auricularia were
then discussed, and its metamorphosis through the
pupa stage into the young holothurian described.
The development of the Asteroidea or starfishes
was exemplified by Prof. Alexander Agassiz's in-
vestigation of various species of Asteracanthion.
The evolution of the Bipamania and Brachiolaria
stages were traced, and their structure compared
with that of the Auricularia. Then the remarkable
transformation of the free-swimming larva into the
young starfish was briefly described, and the ulti-
mate fate of the ciliated processes discussed. The
lecturer then passed on to the Ophiuroidea (Brittle
stars) and in Echinodea (sea urchins), in which the
larva has the form of a Pluteus characterised by
the possession of a large postanal lobe and a pro-
tions of Apostolides and others were discussed, and
visional calcareous skeleton. The recent investiga-
the course of development of the various larval
organs was compared with that which had been
previously described in the Holothurids and Asterids.
In describing the metamorphosis of the Pluteus into
kon's recent discovery of the action of amoeboid
the adult Echinoderm, the importance of Metschni-
Nerodum cells in absorbing temporary larval struc-
tures such as the calcareous spicules, was pointed
out. The life-history of Comatula, one of the
Crinoidea, was illustrated from the older observa-
tions of Sir Wyville Thompson, and the more recent
brys to the Pentacrinoid stage, and from that to the
work of Götte, and was traced from the Pseudem-
adult condition. In conclusion, the various larval
forms were compared, and their possible bearing
upon the classification of the group and its rela-
tionship to the other Invertebrata, was briefly dis-

HE strange and beautiful sunsets of 1883-4, followed so closely upon the volcanic erup tion of Krakatoa, in the Sunda Straits, that the idea has been very generally formed throughout Europe and America that these peculiar atmospheric effects were due in some way to the eruption of that mountain. A piper read before the Meteorological Society on the 13th April by Mr. W. F. Stanley, F.G.S., "Upon certain Effects which may have been produced in the Atmosphere by Floating Particles of Volcanic Matter from the Eruption of Krakatoa and Mount St. Augustine," gave a microscopic examination of some of the dust that fell upon the deck of the bark Arabella at about 1,000 miles from the Krakatoa before the 28th of August last-that is, two days after the period of greatest eruption. The examination, which appears to be the first published, except in a purely mineralogical sense, seems to throw some light upon the subject.

Mr. Stanley analysed principally the forms and dimensions of the particles to ascertain their floating and optical properties. He found the dust was formed mainly of pumice, but that this pumice was for the most part of an extremely light kind, or what he terins overblown-that is, that the ordinary air bubbles that are found in pumice were much extended and blown so thin that they appeared to have been burst into fragments. Under the micro

T5000

cussed.

Thanks and conversazione concluded.

The Mechanical Treatment of Diseases of

UT of sixty-seven candidates the following at the annual meeting of the Royal Society :Prof. G. J. Allman, Prof. J. B. Balfour, J. Baxendell, J. Bell, Prof. W. N. Hartley, Prof. A. S. Herschel, W. H. Hudleston, Prof. H. Lamb, Prof. J. G. M'Kendrick, Dr. A. Ransome, Prof. C. S. Roy, Prof. A. W. Rücker, J. J. Thomson, Lieut. -Colonel Warren, and Prof. M. Watson.

The death is announced of Dr. A. J. C. Geerts, formerly professor at Utrecht, but since 1868 of Japan, where he has filled several important posts, including that of adviser to the department of Hygiene and Public Health in Tokio. His papers on Japan and its natural products have been found of great value, and he had already succeeded in issuing two volumes of an encyclopaedic work, in which he intended to describe all the substances employed by the Japanese and Chinese. Dr. Geerts was only forty.

Mr. Francis Galton will deliver the Rede

lecture at Cambridge on May 28, and take for his subject the Measurement of Human Faculty."

Mr. G. Davidson, President of the California Academy of Sciences, sends us the Astronomical Notes from Bulletin No. 1 of the Academy, to which he appends a report of the meeting held on March 3, when he called attention to some observations on the transits of Jupiter's third and fourth satellites. In the transit of the third satellite on Jan. 15, the satellite was nearly as dark as the shadow, but not quite so large. That 255, the satellite was seen as a circle with a segwas with powers of 120-150. Afterwards, using ment of two-thirds of the disc bright, another third dark or black. Notes from two observers who saw the black transit of Sat. IV. on Feb. 24, were also read. One saw the satellite enter as a white disc on the body of the planet, and subsequently observed it as "black as a drop of ink,"

MM. Henry have been experimenting with photography, with a view of determining the distance and position angle of double stars. They have obtained good results so far.

M. Leveau has been appointed to the place in the Paris Observatory held by the late M. Y. Villarceau.

Altogether nearly 700 tickets for the Montreal Meeting have been applied for by Members and

The Associates of the British Association. "associates" on this occasion are relatives of members.

One noteworthy result of the recent earthquake in Essex is the rise of water level in the wells of Colchester. Within a short time after the shock the level had risen 5ft. above the highest ever known, and on the Sunday after the event it had risen to 8ft., and has remained since at a permanent rise of about 7ft.

scope with high power and oblique illumination these fragments resemble pieces of broken watch glasses. They are of extreme tenuity, being only about 15 of an inch in thickness. There is no doubt that these particles are such as would be likely to float in the atmosphere for a long period the Stomach. The practice of treating patients in currents. It was shown by diagrams that as suffering from chronic dyspepsia, who resist the these particles (which were termed by the author influence of regulated diet and of drugs, by washing bubble-plates) would float with their convex sides out the stomach, which originated some years ago in downwards, consistent with the lowest position Vienna, has recently taken root in America, and has of their centres of gravity. They would formed the subject of a short paper by Dr. W. B. in such position be eminently adapted to Platt, in the Maryland Medical Reporter of March reflect the sun's rays when that luninary was near 8th, 1884. We are there informed that cases most Amongst the electric lighting machines and the horizon and thereby prolong the twilight effects intractable to all other treatments have quickly lamps at the International Health Exhibition or produce an after-glow. At the same time these yielded to this means. The principle underlying there will be, besides those already well known, bubble-plates, being quite transparent volcanic the treatment is to keep the stomach clean, and so glass, they would let the sun's rays pass freely when far as is possible at rest, for a time sufficient to Clark and Bowman, and Oppermann and Fox the sun was at a greater altitude. Mr. Stanley allow of its complete recovery. The operation lamps, Ferranti, Elphinstone-Vincent, Elphinalso showed that many of the bubble-plates were should be performed in the morning, before break-stone-Vincent-Sennett, and some other machines. thick on one edge or on one corner only, in which fast. A soft, red rubber tube is passed gently Altogether, there will be about 5,000 incandescent case they would descend in the air with their down into the stomach quite to the pylorus; with and 350 arc lamps supplied by 62 dynamos. thickest edges downwards, and in this position they this is connected about a yard of common flexible would refract the sun's rays in the same direction tubing and a glass funnel, which is held on a level as the uniformly thin bubble-plates would reflect with the patient's breast, and tepid water is poured slowly into the funnel until a sensation of fulness is experienced; the funnel is then depressed to the level of the waist, and the fluid allowed to syphon turns quite clear. The washing should be repeated out. The process is repeated until the water reevery day for a week or ten days, and during that time the diet should be restricted to milk or a little meat; then the washing may be done every second or third day, and finally abandoned at the end of three weeks. The advantages claimed for this method are that it is efficacious, simple, and safe, and it certainly is worth a trial in intractable cases of chronic dyspepsia, a disease which makes its victims a burden to themselves and their friends, and hitherto has brought but little credit to physicians.-Lancet.

them.

Fletcher's Large Blowpipes.-Mr. Fletcher, of Warrington, has sent us a specimen of his new large blowpipes, for brazing, retort and furnace heating, and repairing machinery in position. The specimen sent burns at full power 300 cubic feet of gas per hour, and requires a 1in. main to supply the gas. A good brazing heat can be got on a 3in. wrought-iron pipe in five minutes by the aid of a blast from a foot bellows, and from the construction of the appliance it remains so cool that it can be held in the hand, a great advantage where it is required to repair machinery without taking it down. These are, probably, the most powerful blowpipes that can be made to work without steam-power blast, and will be found of great utility in any works where gas can be obtained.

Cheap Galvanometer.-Mr. D. Hammond, of Walworth-road, S.E., has brought out a cheap galvanometer, which serves also as a magnetic compass. It is, in fact, a compass mounted over a Communicated by the author. A shorter abstract little coil of wire, and will be of use to dabblers in electrical matters. appeared on p. 163.

The London Central Electric Railway Bill was rejected by the House of Commons Select Committee on the opposition of the Board of Works. That result seems to have been brought about because the Board demanded an exorbitant sum with the object of getting funds to make new for the right to bore a tunnel, beneath the streets, streets. have been of great value. It is a pity, for the experiment would

Mr. Edison has been interviewed recently, and after giving the reporter some interesting figures as to the number of applications for the electric light that cannot be met, seems to have astonished him by the highly original remark that we want to get electricity from coal direct, without the intervention of boiler and engine"-and also dynamos. Mr. Edison thinks it is " surely possible.' Let us hope so.

An achievement in telegraphy is reported by the Telegraphist, whose representative recently paid a visit to the offices of the Indo-European Telegraph Company in Old Broad-street, and

[We do not hold ourselves responsible for the opinions of our correspondents. The Editor respectfully requests that all communications should be drawn up as briefly as possible.] All communications should be addressed to the EDITOR OF

was put into communication with the clerk in LETTERS TO THE EDITOR. nent" ones; albeit his recent names scarcely even charge at Emden. After a few signals the line was opened to Odessa, and afterwards to Teheran. At the suggestion of the operator at Teheran, Kurrachee was called, and the signals still found clear and good. Kurrachie opened the line to Agra, and Agra switched on the line to Calcutta, and to the surprise of all concerned-the Calcutta clerk asked Are you really London?"-the signals were excellent, and the speed not less than 12 words a minute. The total length was 7,000 miles of wire!

It is stated that for the prize of 10,000 lire offered by the Italian Government in connection with the Turin Exhibition, for the best means of transmitting electric energy to great distances, there is only one entry-that of the GaulardGibbs system.

The Philadelphian Local Telegraph Co. use Edison dynamos to supply current for their circuits.

A remedy for pulmonary tuberculosis has been found in aluminium-so it is reported. The fol lowing is the preparation: Metallic aluminium 8 grammes, aluminium hydrate 5 grammes, calcium carbonate 5 grammes, gum tragacanth in sufficient quantity, divided into 60 pills, one to be taken three times a day. As the Lancet quotes the statement without comment, it may be assumed there is nothing very injurious in the prescription.

With the view of encouraging medical research, especially in the direction of preventing disease, Mr. Andrew Carnegie has given 50,000 dollars to the Medical School of Bellevue Hospital, New

York.

The Council of the Linnean Society of New
South Wales have offered a prize of £100 for an
essay on the "
Life-History of the Bacillus of
Typhoid Fever.”

The Oregon having made the fastest trip out to New York has now made the fastest trip home, beating the Alaska by nearly two hours, her time being given as 6 days 16 hours 57 minutes.

USEFUL AND SCIENTIFIC NOTES.

English Express Trains.-At a meeting of the Statistical Society, Lieutenant H. B. Willock, R.E., read a paper on "English Express Trains in 1871, and a comparison between them and those of 1883." It appears that the improvement on the London and South-Western is not great; on the London, Brighton, and South Coast there is a small increase in the number of distinct expresses, but a considerable increase in the journey speeds. As regards the South-Eastern, the service to the Continent has been greatly improved; whilst on the London, Chatham, and Dover there has been an increase in the number of fast trains, but no increase in speed. On the Great Western the running average has increased very substantially. The Great Eastern is credited with having effected & "most wonderful change." Besides vastly improving its road and rolling stock, it has inaugucated a good service of express trains. During the past twelve years the great trunk lines to the north of England and Scotland have all made great

progress.

W.C.

come within the former category. The dictum of
Clemens Alexandrinus concerning Matthew is of
equal value and authority with the same writer's
assertion (in his Gnostic book, the "Erpwpa-ig,")
that Peter and Philip were both married and had
ENGLISH MECHANIC, 31, Tavistock-street, Joveni-garden. Allinson will look at Matthew ix. 10 v. With re-
families. Perhaps, too, in this connection, Dr.
ference to Nebuchadnezzar, I would ask: did "his
vegetarianism cure him of his madness?"-or was
the recovery of his mental faculties?
it a mere sign or symptom of it disappearing with
As for the
amount of brain power" required or exhibited
by Dr. A.'s list of dummies (save perhaps in the
case of Prof. F. W. Newman), I venture to assert
confidently that, outside of their own narrow little
cliques, these persons were and are practically un-
known; and not to make invidious selections-in
the case or two to which I referred, they possess
just the amount of "brain power sufficient to
make a living out of their credulous supporters-
an accomplishment, by the way, shared by the
gentlemen with "three little thimbles and one
little pea one sees upon racecourses, who are not
popularly supposed to be types of the most intel-
lectual class of men in existence. How "a well
person can be more healthy" my knowledge of
physiology fails to enable me to conceive. As for
living to old age: Two people, one a man in the
upper rank of life, the other a retired tradesman,
have died in the town where this letter will be
former was 88, the latter 95, and both meat eaters
posted, within a comparatively recent period: the
during their whole lives. I don't want to live over
95 myself; and decline to diet myself on onions and
oatmeal to effect that end, when I have ocular de-
monstration that it is attainable in a way so much
more consonant with the practice of all the best,
greatest, and most intellectual men who have ever
of the human race.
lived in the world, and helped towards the progress

All Cheques and Post-ofice Orders to be made payable to
PASSMORE EDWARDS.

J.
In order to facilitate reference, Correspondents, when
speaking of any letter previously inserted, wil oblige by
mentioning the number of the Letter, as well as the page on
which it appears.

much as he knows, but no more; and that not in this
"I would have everyone write what he knows, and as
only, but in all other subjects: For such a person may
have some particular knowledge and experience of the
nature of such a person or such a fountain, that as to
other things, knows no more than what everybody does,
and yet, to keep a clutter with this little pittance of his,
will undertake to write the whole body of physicks; a vice
from whence great inconveniences derive their original."
-Montaigne's Essays.

IN

STAR MAGNITUDES-THE DIVISIONS
SATURN'S OUTER RING-THE
5th AND 6th STARS IN THE TRAPE-
ZIUM OF ORIONIS-VEGETARIAN
ISM A BOOK TO BE BOUGHT-A

SNUB FOR SOUTH KENSINGTON

SPORTULARY SCIENCE-THE PHY.
SICAL CAUSE OF THE AFTER-GLOW
-SUNLIGHT ON WATER-STEREO-
SCOPIC PHOTOGRAPHS OF THE MOON
-CONVERTING HOUR ANGLE AND
DECLINATION INTO ALTITUDE AND

AZIMUTH.

seemingly unaware that Zöllner, by the aid of his
[22684.]-CAPTAIN KING (letter 22616, p. 165) is
polarisation photometer, determined that each suc-
ceeding star in the ordinary scale of magnitudes
This determination was made from an examination
emitted just 0.363 of the light of that preceding it.
of 293 stars from the 1st to the 6th magnitudes.
Rosen employing the same apparatus, but selecting
stars varying between the 5th and the 95th magni-
Let us take
0.380 as the mean; then a star of the 2nd magni-
tudes, made this quantity 0.398.
tude will shine with 0-350th of the light of one of the
1st a 3rd mag. star with 0-144 of that of a 1st
mag star, and a 4th, 5th, and 6th magnitude star
with the relative brilliancy of 0.0549, 0·0209, and
0.0079 respectively. Sirius, according to this scale,
should shine with 3.61 times the brilliancy of the
standard star of the 1st magnitude, whatever that
may be.

In connection with letter 22619 (p. 166), I may
remark that Proctor in his Saturn and its System
(a book which should be in the library of every
astronomer), speaks of the various divisions in
Saturn's outer ring which have been observed from
time to time by Encke, the Struves, Dawes, Jacob,
&c.; and suggests the idea that while what is known
par excellence as "Encke's division" is probably
permanent, others may be only transitory, and ap-
pearing and disappearing in various parts of the
annulus. There is no theory of the condition of
the rings, tenable on mechanical grounds, save
that of their being composed of discrete particles;
and this being so, temporary gaps in annuli so
formed may well be imagined to occur.

In reply to the question with which Mr. Dunlop concludes his letter, I may say that I have seen the 6th star in the trapezium of Orionis, and always see the 5th with 4in. of aperture. I believe the 6th to be certainly variable, and the 5th possibly so; but as regards the latter, it is essentially au atmospheric test, as contradistinguished from an optical The Ordnance Survey.-A Blue-book just or merely instrumental one. On this subject your published gives an account of the progress of the correspondent may with advantage consult the Ordnance Survey to the end of last year. During addenda to Crossley and Gledhill's admirable the year 1883 the survey has been carried on from Appreciating so highly as I do the valuable work "Handbook of Double Stars," pp. 18 and 19. ten different centres in the counties of Brecknock, Dr. Klein has done in selenography, I grieve to find Cambridge, Carmarthen, Cornwall, Devon, Glou-him making so dogmatic an assertion as that with cester, Hereford, Leicester, Montgomery, Norfolk, which Mr. Dunlop credits him. The two Struves Northampton, Nottingham, Somerset, Stafford, Suffolk, Warwick, Wilts, and which is well within the theoretical light grasp. Rutland, Salop, estimated the magnitude of both these stars at 11.3, Worcester. The survey of the entire counties of ing power of 4in. of aperture. It is the proximity Cornwall, Gloucester, and Salop has been completed, and the work is proceeding in the other of the 6th star to a, rather than its inherent faintCounties named above. In addition to these it is ness, that makes it such a difficult object, especially expected that the survey will extend during the Dr. Klein states that he cannot see the 6th, or even under unfavourable atmospheric conditions. When ensuing year into Lincolnshire, Huntingdonshire, the 5th, star in the Trapezium of 9 Orionis with a 4in. Cardiganshire, and Merionethshire. The only counties that will then remain to be taken up are object-glass, he makes an allegation as to a matter Anglesea, Carnarvon, Dorset, Pembroke, and does not believe that other observers, of experience of fact. When, though, he goes on to say that he Radnor. The area surveyed during the year 1863 at least equal to his own, are speaking the truth was greater than in any preceding year, having when they assert that they have perceived these amounted to 2,586,087 acres, and the rate of pro- objects with that aperture (Burnham has seen the gress now attained is sufficient to insure the survey 6th star with 34in. !), he simply expresses a matter of of the whole country being finished by 1888, and opinion in so offensive a form as to require no to admit, therefore, of the publication of the maps contradiction, nor even notice. being completed in 1890.

THE rainfall during March at West Molesey, where it is measured by the official water examiner, Sir Francis Bolton, was 1·14in.

Since writing the above, I have seen letter 22659 (p. 188), and once more I must ask Dr. Allinson among "Eminent Vegetarians." for his authorities for including the names he gives As for Lord Byron, it is ridiculous to quote from the Dietetic Reformer the passage concerning his eating potatoes and vinegar. He was a very vain man, with a nervous dread of getting fat, and I thought that everybody knew how he took vinegar to make himself thin. I can find no record of "Wm. Hoyle, the statistician." Pascal was a religious ascetic, who may, or may not, have confined himself to a vegetable diet. He also wore an iron girdle, studded with spikes, next to his skin, and killed himself prematurely at the age of 39 by this and cognate tomfoolery. What Abd-el-Kader ate I do not know-a remark which applies to Lamartine, Dr. Adam Ferguson, and Garibaldi. It is in such cases as these that Dr. Allinson is bound to give definite contemporary authority, and not extracts from Food-of-Health-shop journals. Daniel refused to eat the King's meat and wine, and took pulse instead; but the reason for this is definitely stated, and there is no vestige of proof that, at any other part of his life, the prophet was a phytophagist. John the Baptist was not a vegetarian, for he ate locusts. I know that a silly assertion has been made, by people who know nothing whatever of Eastern customs, that John ate locust beans; but St. Matthew says definitely (Chap. iii. 4) ἡ δέ τροφὴ αὐτοῦ ἦν ἀκρίδες. After looking out the word 'Akpig in the lexicon nearest to his hand, Dr. Allinson may read the recent account of Lady Ann Blunt of the ways in which that most conservative of all people, the Arabs, cook and eat locusts at this instant. It may suffice to say, finally, that Chatterton was an insane impostor, who poisoned himself when he was 17 years old; being in such dire distress that he could not buy a single scrap of food, animal or vegetable, at all.

What Houzeau did for the advanced astronomer has just been done for the beginner in an excellent in his "Répertoire des Constantes Astronomique," little book by Mr. W. T. Lynn (formerly of the Royal Observatory at Greenwich), which he has called "Celestial Motions," and which every young most accurate numerical data and details of the astronomer who is anxious to possess the latest and bodies composing our Solar System, should obtain forthwith. Comets and Meteoroids find a place in Mr. Lynn's tiny volume, there is a very good readable précis of the History of Astronomical Dischapter on the Fixed Stars, and an interesting and covery; a glossary of the technical terms employed concluding the treatise. Dickens said but hardest to write," and it is only those possessing too truly that "What is easiest to read is the an intimate acquaintance with the subjects treated of by Mr. Lynn who will be able to appreciate the very great amount of painstaking and conscientious labour which he must have bestowed upon his capital little work,

The action of the Drapers' Company in connecI must ask Dr. Allinson to forgive me if I say tion with the City and Guilds of London Institute, that I do not think that letter 22626 (p. 167) demands to which I referred in letter 22505 (p. 75), has not any detailed reply at my hands. He would seem been without effect. It has evidently given heart to confuse merely notorious people with "emi-of grace to those members of the executive committee

whose sole thought and care is for the advancement of technical education, as contradistinguished from the compact clique who have ab initio tried to exploit the whole affair in the interest and for the benefit of the Brompton ring; and the same spirit of independence which led to the original appointment of Mr. Magnus as director, has happily been once more exhibited within the last few days in the elections to the Professorships of Chemistry, Engineering, Mechanics, and Physics respectively. That efforts will still be made to provide berths for the friends and hangers-on of the "genteel" element in the executive, but few will be silly enough to doubt. Meanwhile, though, the smack in the face which the South Kensington Ring have received by the appointment of Doctors Armstrong, Unwin, Henrici, and Lodge to the four professorships of which I have spoken, affords gratifying evidence that the time-honoured freedom which has characterised the civic guilds is yet proof against both the bullying and the blandishments of the Brompton cabal and their tools. What the independent members of the executive committee have now to guard against scrupulously are specious and plausible attempts to introduce such utterly irrelevant subjects as astronomical (or "solar") physics, and the like, into the curriculum of the Institute, in order that a lectureship or lectureships may be provided for any person or persons who may be anxious for a genteel form of out-door relief. I hope to get the earliest authentic information, should any such attempt be made; and should such reach me, I shall avail myself of the earliest opportunity of speaking on the subject in these columns in a very definite manner, indeed.

The formula for converting R.A. and declination (or, rather, a Star's hour-angle or distance from the Meridian and its declination) into altitude and azimuth, for which" Warragul" asks in query 53600, will scarcely be intelligible without a figure, which I consequently give.

Z

Mr. Mee might write to the London Stereoscopic in the introduction to his "Red Star Catalogue,"
Company.
Mr. Birmingham speaks of having employed a
power of 53 "generally," upon a 4 refractor.
"With this," he says, "I could well define the
colours of stars down to 10 magnitude." In his
letter upon p. 534 of the last volume, Mr. Franks
says: "A good Huyghenian eyepiece of 90 to 120
diameters is as useful as any.' I see, however,
that Mr. Espin and "F.R.A.Š." have used 160. I
am obliged to "F.R.A.S." for his description of
M. Montigny's contrivance for the estimation of
star colours. I shall not, however, be able to avail
myself just now of any such device. In such con-
trivances is not the artificial star apt to introduce a
source of error? No matter what the brightness
of the star, the artificial star must always be of the
same brightness, and will the one not affect the
other in matter of colour? Also, how are the
purity and uniformity of the coloured discs to be
insured? And will the contrivance be of service
with small stars, say below 7 mag.?

Н

M

A

IS

N

I must thank Mr. Gore (22484, p.142) for his prompt

Here PN is the latitude of the observer's sta- courtesy. With the exception of 6 Auriga and a

and

tion. This we call .

90°

PZ is the co-latitude, or 90° — ¢.
Cephei, Prof. Pritchard's results are in pretty close
accordance with my own; but I will comment upon
PS is the star's polar distance =
this point again. I am sorry that I cannot answer
being the star's declination.
ZS is the star's zenith distance. This we think I have a single observation of stars in Mono-
Mr. Gore's query about 29 Monocerotis. I do not
call Z; then, of course, SA is its alti-ceros-a circumstance for which the weather and
tude.
ZPS is the star's hour angle or distance blame. With reference to what Capt. King says,
the smoky atmosphere of Glasgow are mainly to
from the meridian. We call this P.
I think I have read in "ours" that when the com-
PZS its Azimuth, which we call A. Then
having the two sides PS and PZ, and
the included angle ZPS in the spherical
triangle PZS; we have to find the
remaining parts.

Let fall the perpendicular SM from S upon
ZMH. First we want PM. Now-
= cos. P x cot.
(1)
= cos. (PM + ) × cot. P x
co-sec. PM
(2)

Tan. PM
Cot. azimuth

and

Cos. zenith dist. = sin. (PM + ) × sin. ♪ x

sec. PM

(3)

Let us work this out in figures. Suppose that "Warragul" lives in York, and wishes to know the altitude and azimuth of Arcturus when that star is 4h. 12m. east of the Meridian.

Here is a paragraph from that amusing and readable book, "About Photography and Photographers," by Mr. H. Baden Pritchard, which deserves all the publicity that can be afforded to it by its repetition here. "If," says Mr. Pritchard, "other proof were wanting that prizes in money spontaneously offered are valueless in influencing research one way or the other, it is afforded by the fact that the Government has, during the past five years, spent twenty thousand pounds in the endowment of research. The money may have been well or ill-spent-we fear those who had most influence got most of it, and the needy inventor without friends is as needy as ever;-but can any one point to a single investigation of value which would not have been undertaken but for this grant"? When formula. The star's hour angle 4h. 12m. Then the latitude of York 53° 57' is the of our = 63°, our will the long-suffering animal, John Bull, learn the truth of this for himself, and exhibit sufficient P, and is the declination 19° 47′ of Arcturus. public spirit to act upon this knowledge? When-By equation (1). ever he does, he will forthwith turn out any Government that persists in annually picking the National pocket to subsidise the impudent, greedy, advertising ring of quacks and jobbers who alone benefit by the existing system.

Mr. Ballot's letter (22652) on p. 185, seems to me to possess peculiar interest just now, when the mot d'ordre has gone forth that the recent wonderful exhibitions of fore and after-glow are to be set down to Krakatoa-the whole Krakatoa, and nothing but Krakatoa. Certainly, if this phenomenon had its origin in the existence of a mass of dust, cosmical or volcanic, the "exceptionally heavy rains," of which your correspondent speaks as having fallen, and continuing to fall "almost daily," must have washed such dust down to the earth's surface, and so put an end to the display. From certain personal experiences I was, in the outset, strongly tempted to refer the wonderful spectacles which we have been witnessing to the intrusion of a mass of meteoric dust into the upper regions of our atmosphere. The more I examine the matter, though, the more I am disposed to believe that I was in error in this assumption, and that, as Mr. Ballot concludes by saying, "there seems to me decided proof . . that aqueous vapour plays an important part in producing the after-glow."

this, and which may be useful to some of your readers. It answers admirably.

I may premise that my telescope, 9ft. 3in. focus, is raised, so that the axis is 5ft. 6in. from the floor, which gives a view through the shutters over the ring of the roof of about 15' altitude. have a platform 4ft. 6in. long by 4ft. wide, and My observatory is 12ft. square internally, and 1 2ft. 6in. high, on castors, which follows the telescope (an altazimuth 124in.), from which 1 observe as if I were on the ground. This commands, when standing, about 45° altitude, and from it I can see through my finder at any angle up to vertical, so that all objects can be found while standing on the platform. It has a rail round three sides 2ft. lin. high, and the same three sides have a flange rising 3in. above the floor to prevent the observer, chairs, &c., falling off. I have been accustomed to stand, but this is rather tiring if one observes for long. The rail forms a convenient rest for the feet when using the chair, and also a step to mount into it.

The difficulty of Mr. Harcourt (query 53571, p. 198) will disappear if he will bear in mind that light falling on the ground is reflected irregularly from [22685.]-I WAS very glad to see the letters (on millions of points; each of such points being, as it pp. 120 and 121) of "F.R.A.S." and Mr. Espin were, a kind of independent focus from which rays upon star colours. I can only hope that both of emanate. In the case of the surface of a river, or these gentlemen, and others, will make further that of a looking-glass, the rays are regularly re- similar contributions. The comparison of the tints flected, and send to the eye of the observer an given confirms some of the ideas I put forward in image well or ill defined of the object, such as the letter 22492 (p. 55). There are one or two excepsun, from which they emanate. All this is explained tions, however: notably, Capella and Procyon; but in every primer of optics that was ever published. this was what was to be expected. It would be If your correspondent will get a polished bit of curious matter for inquiry whether or not the stars window glass and lay it flat when the sun is shining, which show the peculiarities mentioned in the quohe will, on removing his eye to a suitable tation from "Celestial Objects" which is given at position, see an image of the sun reflected the end of letter (22492, and in that most valuable in it. Now let him pound this same bit communication from Mr. Franks in "ours" for of glass in a mortar, and once more put the June 20, 1879, show any tendency to grouping or powder in the Sun. The luminous image will have association. Mr. Proctor's researches would lead disappeared, but the scattered reflection from the one to expect that they would. I will look through innumerable particles will convey the idea of a my lists, and select those observations of star greyish white powder; albeit all we have done is colours which seem trustworthy, and send them for stand, 12in. square at the top, with the legs, which In the chair, as drawn in the sketch, I have a to rearrange them. letters of Mr. Espin and "F.R.A.S."-what is the to 2ft. square at the bottom. Into the shrouding comparison. One important point is raised by the are 24in. square and stop-chamfered, expanding power which is best adapted for observations of this A at the top of the stand, which is 64in. deep, and kind, a low or a high one? I have always thought 14in. thick, at in. from the bottom is mortised it best to employ my 45 e.p. and I observe that, block B, 8in. wide and 3in. thick (shown by dotted

lines), through which is tapped the bed screw to receive the screw which carries the chair.

To the top of this screw is fixed a circular block C, Sin. dia. and 3in. thick, the shaft of the screw, left square for the purpose. 34in., being let into and through the block, and well pinned from the outside. I then took a Windsor chair, and cutting off the legs, securely fastened it to the circular block, the bottom of the chair being planed true to fit the block, and then glued to it, with dowels also let into the chair.

The screw is 24in. dia. and 15in. long, and is then turned down to 1in. dia. for 15in. more, passing through a circular bearing D 12in. thick and 7in. dia., about 12 in. below the bottom of the bed screw. This keeps the screw and chair perfectly rigid and steady. The screw runs easily, and the chair by it can be raised or lowered at pleasure. When at its lowest, the chair rests on the top of the stand, and is then 3ft. high, and it can be raised to 4ft., which is the right height when the telescope is vertical. The whole is made of well-seasoned beech.

The platform is a very great advantage, and I may say in an equatoreal it would have to be smaller to move more easily, as the eyepiece changes its position much more; but it might be adapted, and the way that all positions can be commanded, and the ease and pleasure of doing so, can only be appreciated by experience. The chair is, of course, placed on the platform. Fordingbridge.

T. Westlake.

COMET PONS-BROOKS. [22687.)-I AM very glad to find, from the remarks of Mr. Gemmill (p. 122) that my estimates of brightness were not very far wrong. When I came to compare my estimates with the magnitudes of Heis, and found that he had both a Pegasi and a Andromeda as second magnitude, I took it for granted that I had made a mistake, and this opinion was strengthened when I found that Argelander also had both of the stars as second magnitude. I overlooked the fact that neither of those authorities divided their magnitudes as close as "tenths" in their uranometry.

I am also obliged to Mr. Gore (p. 516 of your last vol.) for his explanation in regard to the brightness of and Cygni. He, however, misunderstood my difficulty. It was with regard to a and not y Pegasi; but the letter of Mr. Gemmill has cleared up the matter.

This comet bothered me considerably in trying to estimate its brightness. I had, of course, often observed previous comets, both with the telescope and the naked eye, but had never tried a regular and systematic series of observations, with a view of determining the relative brightness, and I at once found it difficult to compare a diffused mass of light with a compact point like a star. I notice, in the April number of the Observatory, that Mr. Sawyer also found some difficulty in comparing the comet with the neighbouring stars; but he succeeded better than I did, being an older and more experienced observer. Still, I find, upon comparing some of my observations with his, that our results fairly accord.

that can be accomplished by those using apertures of 8in. and upwards is unlimited. I note that, through some unfortunate mishap, the "initial " appear on his drawing, and thus somewhat mar the letters which Mr. Bone uses in the context do not interest and value of the same.

Mr. W. H. Davies, F.R.A.S., still a number of I have, through the kindness of our secretary, lithographed key plans of Fracastorius, copies of which I shall be pleased to send to any who can see their way to render us assistance.

of Godin and Agrippa, and as the same is of someI have also prepared a key plan of the region E. what simple nature, I have ventured to send a copy herewith, which, perhaps, our good Editor may be able to publish with this letter. I have divided it will facilitate the insertion in their correct places, into degrees of Lunar latitude and longitude, which detail which we hope to get mapped. This region, compared with each other, of the more minute besides containing separate objects of unique interest, such as Hyginus N., presents examples of with regard to the same: "East of Agrippa and almost every kind of formation. Neison says, Godin is a mountain region of very irregular nature, full of bright craters and craterlets, only the general appearance of the larger objects having as yet been drawn."

length of tail between Dec. 27 and 28, but says, staring or stargazing. The amount of useful work nothing about its appearance on Dec. 29. I do not know whether the comet was observed on that night at Washington. I suppose not, however, as Nachrichten, no mention is made of that date. The in the observations as published in the Astronomische increased brightness and length of tail was much more noticeable to me on the 29th than on the 28th, and at the time forced itself so on my notice that I forgot about the tail being faintly seen to 3 the night previous. As Mr. Gemmill remarks, I have since learned that the strange appearance of comet on Jan. 13 was seen by various other observers at the same time. I notice that a paper was read before the Paris Academy of Sciences on Feb. 11, by M. Perrotin, of Nice, on the appearance of the comet on Jan. 13 and 19, but I have seen no acmeeting of the same body on March 10, M. Faye count of what the paper was. Also that at the In regard to the matter of the tail, I would say changes in the appearance of the late comet were read a paper in which he held that the singular that this was first suspected by me with the tele-due to the rapid change in the point of view of the scope on Nov. 30. That was the only observation comet itself, as seen from the earth. His theory made by me in November, for I bicycled nearly all of our county roads during that month. On number of the Comptes Rendus; but I am not well was to be published and illustrated in the next Dec. 3 I was not so positive about seeing the tail; enough acquainted with French to read the article but on Dec. 5 I felt pretty sure of it again. I was with interest, even if it were accessible to me. unfortunate, however, in seeing the tail with the Probably some reader could explain M. Faye's naked eye, for just about the time the weather would clear up the moon would begin to put in its theory if the matter is of sufficient interest. appearance, and vice versa. On Jan. 13 I saw the comet with the naked eye through light mackerel clouds before going up in the observatory, and I must say I was considerably surprised at its brightness, and expected to see, of course, something like a respectable tail when the clouds got away. It looked so bright between the clouds, that I could hardly believe it was the comet, and was wonder- SELENOGRAPHICAL-FRACASTORIUS ing at first what star it was; but when the clouds rolled off, the moon was up and the sky bright, and my expectations disappointed, for the tail was very faint, if at all noticeable. On the 17th the tail was very prominent, the moon being far out of the way. I think it probable that the tail was visible to my unaided eye on Dec. 28 and 29; but as I was not positive about it, I preferred to err on the side of uncertainty. By the way, it seems to me that something must have been going on in the comet about that time. On the 27th the tail was only 1 long to me; on the next night it was plain for 1, and could be traced faintly to 3; but on the 29th it had shot out a straight, bright streak of light to the length of 3 certainly, and could be seen faintly to 4 or so.

On the first night the nucleus was star-like and evident, nothing around it except the coma, but on the next two nights the nucleus bothered me, as I could not satisfy myself as to whether it was distinctly stellar or strongly condensed. In the March number of the Sidereal Messenger, I see that Commander Sampson speaks of the marked increase in

Our printer made a curious mistake about my name the last time: but I suppose my writing was bad, and the signature being the only part not written with the type-writer, he had to guess at it. Baltimore, U.S.A., April 23.

W. H. Numsen.

AND NEIGHBOURHOOD-REGION E.
OF GODIN AND AGRIPPA.
[22688.]-IN the letter which accompanies his ex-
cellent drawing of Fracastorius and neighbourhood,
and which appears on page 165 of the present
volume, the Rev. J. Bone, M.A., is kind enough to
refer in flattering terms to the selenographical work
which is being undertaken by the Lunar section of
the L. A. S. I am very hopeful that his interesting
remarks and appeal will induce many of our readers
to volunteer their services in this cause. Referring
more particularly to the drawing itself, I would call
attention to the fact that a number of craterlets are
shown by him, more particularly to the N. and W.
of Fracastorius, which do not appear in Neison's
map, nor on any others with which Tam acquainted;
all these, of course, require confirmation, and thus
furnish very suitable work for the possessors of
telescopes of moderate apertures, the employment
of which on systematic work like this (and which
grows in interest as one proceeds) is far more likely
to produce good results than desultory moon-

Here we have, then, a further field for our endeavours. Who will help? W. Goodacre.

Clova-road, Forest-gate, E.

REVIEW OF THE LIVERPOOL ASTRONOMICAL SOCIETY'S SESSION, 1883 -1884.

[22689.]-IT is seldom that a society wins popularity so rapidly as the Liverpool Astronomical Society has done. The rapid increase of members has, I think, been almost without precedent. Looking back over the numbers of the Abstracts of the Session just closed, I find that no fewer than fiftyfour new members have joined during the session. Considering the many attempts that have been made to found and work amateur observing astronomical societies, which have all resulted in failures, the Liverpool Astronomical Society may well be a source of wonder and congratulation. Even the Selenographical Society, made up as it was of the first men in the world in lunar work, has come practically to an end. are some seventy members, but nothing is published and nothing done in the name of the society, as was pointed out in your columns some time ago. The flourishing condition of the Liverpool Society is due to the energy of certain officers, more especially the secretary, whose zeal is beyond all praise. Looking over the abstracts of

There

An Optical and Instrumental sectionis to be formed ext session under Mr. A. H. Wassell, a well-known and esteemed writer in these pages and Photo-ably been seen by Mr. Burnham, with 3in. aperture graphic and Meteoric sections will also be undertaken it is hoped.