minor axis by the major axis, the result being the FOR electrical and magnetic experiments, amateurs sometimes find it desirable to mount cosine of the angle, which may be found in any table of sine and cosines. The formula is as fol-magnetic needles on rigid bearings, and without the aid of untwisted silk or other suspending fibres. The accompanying figure illustrates a method by

After the glass has passed through A, prism and lenses; B, box containing diaphragm the machine, the protective coating (wax is generally used) is not removed, but is left on to keep the and galvanometer; C, clockwork for sidereal glue off those parts which are not intended to chip. The glue is then applied in a thick layer to the ground portion, and the process is carried on as

"Now Keeler knows all that is worth knowing about the spectroscope, and we studied the matter out together. It is known that the spectrum of each and every comet so far observed consists of three bright hydrocarbon bands, in the yellow, green, and blue portions of the image. The conAN ASTRONOMICAL MACHINE THAT DIS-tinuous spectrum underlying these bands is so faint

THE METEOR GETS IN RANGE, "ELECTRICITY DOES three central bands are absent, the light of the star THE REST."

The comet-seeker has a hard time of it, exposed as he must needs be, to all sorts of weather, in the open air, with no protection from the wind, at all hours of the night, sweeping over every square degree of the sky with all his powers "The comet-seeker stood on the west wall of the of acuteness at the highest pitch, lest the platform. It was a bright moonlight night, and faintest object should be overlooked. No moon- therefore the instrument was not in use. Prof. light hours can be utilised. There is nothing Barnard uncapped the lens, and showed the prism to show for an unsuccessful night. In any other in front of the objective. branch of astronomical work the observer would

هد

APRIL 10, 1891.

ENGLISH MECHANIC AND WORLD OF SCIENCE: No. 1859.

distant body-barely visible to the eye through the
same object-glass-was instantly detected, and my
experiment proved a complete success!
may be sure I feel pleased; not so much
for the honour of the thing (which we all share), but
at the immense saving of valuable astronomical

time.'

You

paratively scarce, and are not phosphatised. The
from the Belgian chalk the remains of a saurian
fish-remains are similar in all these chalks; but
upwards of 50ft. in length have been unearthed.
This phosphatised chalk is at present known in one
made along the outcrop of the same beds, it has not
pit only in England, and, though search is being
at present met with success.

SCIENTIFIC SOCIETIES.

"While speaking, the professor had been carefully covering up his pet instrument, and he descended to his office. There I was shown the multitude of plans which had been developed in the preliminary experiments. The inventors had first attempted to work with a single slit in the diaphragm, representing the position of the principal hydrocarbon band; but on studying the existing charts of BRITISH ASTRONOMICAL cometary spectra, they soon found that the position occupied by any given band was somewhat variable, and all three had to be utilised. One at least of these is sure to be in the normal position, and detection of the comet's presence is infallible.

"By this time I had been so impressed with the grandeur of the invention perfected by these modest workers in astronomical science, that I felt impelled to decline their generous offer of further entertainment, and, full of the subject, returned to San Jose with their entire permission to make the facts public. My notes were hastily written, and this resulting description is not, perhaps, entirely clear in consequence. But I am happy to be allowed the honour of communicating to the world this brief sketch of a new invention, which will revolutionise at least one branch of astronomical "Collis H. Barton. @investigation.

"San Francisco, March 6, 1891."

TH

ASSOCIATION.

ridges visible thereon, is traversed by a system of
more remarkable than those discovered in Plato,
light markings and associated light-spots, even
Fracastorius, and Archimedes. Between January,
of the section, with a view to confirm his observa-
1881, and August, 1883, Mr. A. Williams recorded
objects will, of course, receive the close attention
tions. The hexagonal shape of the border of Ptole-
at least 85 of these faint, light-streaks, which
maus is far from being a solitary instance of the
tendency to a six-sided figure among the larger
class of walled and ring-plains. The same pecu-
liarity may be noted in the case of Copernicus, and
in many other of the so-called rings, large and small.
arrangement of the mountains and highlands of
which it is made up have in many places no appa-
The explanation of this, and also of the fact that
rent relation whatever to the contour of the floor
(a structural condition also not confined by any
of the framers of hypotheses. In describing the
means to Ptolemaus), may be left to the ingenuity
eastern wall, Mr. Elger referred to a remarkable
gap in it, where for a distance of three or four
miles there is no barrier at all between the floor and
the outside country. In conclusion, he contended
for the importance of the observer acquiring a cor-
rect appreciation of the actual size of the formation
or any other formation, than they can
he studies, so as not to underrate the true signifi-
the section not to attempt to draw more of Ptole-
cance of details. He also urged the members of
"Sun-reasonably hope to finish during the course of three
or four hours' observation, and to devote them-
maus,
selves to a limited area, or their work would not
possess any great selenographical value.

HE fifth ordinary meeting of the above Associa-
tion was held at Barnard's Inn Hall on
March 25, the President, Captain W. Noble, in the
The following papers were announced as having
chair.
been received;"Ptolemaus," by T. Gwyn Elger;
"John Michell, Astronomer and Geologist," by
John Richard Sutton; "The Canals of Mars," by
A. Stanley Williams; "The Determination of Star
Colours," by W. S. Franks; "On Observing Star
Colours," by the Rev. W. R. Waugh; "The Deter-
Selenographic Studies," by Victor Nielsen; "Is
mination of Star Colours," by B. T. Hopkins;
the Moon cased in Snow?" by S. E. Peal; "The
glows," by Rev. S. J. Johnson.
Solar Star-Cluster," by W. H. S. Monck;

66

66

The President said: In his inaugural address, referring to Mr. Peal's glacial theory of the moon, attempts to he had said, "He" (Mr. Peal) account for the strange and so far inexplicable EDISCOVERY OF PHOSPHATIC CHALK streaks which radiate from Tycho and other lunar

IN ENGLAND.

HE discovery of a deposit of phosphatic chalk Tindipit near Taplow has been announced, and as we annually import about 40,000 tons of this valuable manure from the Continent, the discovery is of much interest. At the request of the DirectorJeneral of the Geological Survey, Mr. Strahan undertook the investigation of the deposit, and laid he results before the Geological Society of London n the 25th of March. The pit from which the riginal specimen had been collected is old and In lisused, but has in former years yielded a large quantity of chalk for agricultural purposes. he lower part it exposes flint-bearing chalk of the isual character, and in the upper part two bands of the brown phosphatic chalk, 8ft. and 4ft. thick espectively, which are separated by 12ft. or 14ft. of nearly white, flintless chalk.

formations by supposing them to be electrical lines of force, exercising a repellent influence on the Mr. Peal had written to him to say that meteoritic dust which must fall so copiously on the moon." his theory had been wholly misrepresented, and a single electrical surface discharge, which had that he considered the rays as marking the track of He (the President) did not removed the meteoric dust and so exposed the clean surface of the snow. think Mr. Peal had improved matters. The fall of meteoric dust upon the moon must be very considerable; practically, it must be the same, surface the snow was cleared of the dust in places, and for surface, as fell upon the earth. If, therefore, there were no continued action to keep those places clear, they would soon become as completely covered as before. However, if Mr. Peal considered sorry; it was certainly unintentional on his part, that his theory had been misrepresented, he was Mr. T. Gwyn Elger read a paper on "The Lunar Under the microscope the brown chalk proves to and he begged to offer Mr. Peal his apologies. e a purely organic deposit. The fine white mud emoved by washing in water consists of some Walled-Plain Ptolemaus," which was illustrated xtremely minute bodies common in the chalk, by lantern-slides prepared by Mr. A. Wheeler and nown as rhabdoliths, coccoliths, and discoliths, exhibited by Mr. Maw. After describing the telehich, though of doubtful history, are believed to scopic aspect of this magnificent circumvallation e of organic origin. The brown sand is made up under a low sun, and the more prominent details f the following organisms, taken in order of their which may be seen under these conditions, even in Firstly, the shells of foraminifera; a small achromatic of 2 in. or 3in. aperture, he said bundance. econdly, small, crystal-like prisms broken from that it is an hexagonal-shaped inclosure some 115 e shells of the Inoceramus, a common chalk miles in diameter, the area of the floor being about ollusc; thirdly, comminuted bones, teeth, and 9,000 square miles, or approximately equal to the cales of small fish; and, lastly, small oval pellets, combined areas of the counties of York, Lane exuvia of fish, which were probably about the cashire, and Westmoreland. Its dimensions are so ze of sprats. The foraminifera include numbers of great, that, were it possible for anyone to be enera common in the chalk, such as Globigerina, stationed on the floor near the centre of the ring, extularia, Cristellaria, and Planorbulina. They he might easily imagine that he was standing on a re, generally speaking, filled with an opaque mass boundless plain so long as he looked only to the f phosphate of lime, the shell itself being some- north, east, or south, as not a peak or any indicames carbonate of lime and sometimes phos- tions of the existence of the complex and massive hate in a translucent form. The small prisms border would be visible. Even on turning westcom the Inoceramus shells are also partly converted wards, one object only would break the monotony ito phosphate of lime, while the fish-remains and of the horizon, and this the upper one thousand the western wall. The rough, rocky barrier of e pellets consist, as usual, principally of this sub-feet of the great peak n (nearly 8,700ft. in height) on Ptolemaus is broken up by many longitudinal and cross valleys, and abounds in depressions, large and small. On the north-west there is a wide, bright plateau falling gently towards the border, which, among other interesting features, includes a very noteworthy crater-row running from the wall to the S.E. side of a large crateriform depression, Hipparchus r, which has two deep contiguous craters on its S.W. side. The late Rev. Prebendary "Webb's Furrow." Webb found that the direction of this crater-row was continued down the eastern slope of r by a The shadow of the delicate cleft, now called Hipparchus has a central mountain, easily visible mountain is very conspicuous and beautiful under a moderately high sun. "common teleat sunrise, when the three peaks which surmount it and the crater near its highest point is may be well observed in very scopes," very clearly visible on the wall in instruments of moderate aperture. The north and north-east border, and the neighbourhood of Herschel and Herschel d, include a vast amount of detail hitherto unrecorded, but which will be mapped and catalogued in the monograph of the formation which is being prepared under the auspices of the Association. The floor, in addition to the many craterlets and saucer-shaped depressions and low

ance.

By treatment with acetic acid a portion of the arbonate of lime which cannot be removed by ashing can be dissolved out, the phosphate of me being unaffected by the process. This phoshatised portions of the organisms can thus be eparated out from those which have remained in heir original mineral condition. In some cases ne phosphate has so completely filled the foraminiera that it has penetrated the innumerable little ores, or foramina, in the shell, from which these In such the removal rganisms receive their name. the shells by acetic acid leaves an internal cast phosphate, covered with a short crop of little air-like processes, each of which is the cast of a

ramen.

A comparison of the French phosphatic chalk ith that from Taplow establishes their identity In general appearance they are eyond doubt. distinguishable, while the same organisms, in a milar condition of phosphatisation, occur in both. hey occupy, however, about the same position in he chalk system. The Belgian deposit is somewhat ewer-later, in fact, than any chalk existing in ngland; but in appearance and composition it osely resembles the English phosphatic chalk. 'he microscope, however, discloses the difference in the Belgian rock foraminifera are com

at

on

Mr. Green then gave a paper on "The Lunar Seas," which was also illustrated by means of the seas follow a definite order of arrangement, the graph of the moon, it will be evident that these lantern. He said: On examining a map or photothe centre of the disc. There is not a single instance smaller being near the limb, and the larger nearer of these dark areas extending to the limb, and larger still are revealed by libration, they are not although large craters may be found there, and also be observed that even when the dark formathere is still an unbroken line of bright surface filled with dark matter like the seas. It should tions come very near the limb, as on the north-east, beyond them, so that we have no reason to expect the earth. The brighter portions of the lunar that similar blotches exist on the side turned from are lower, comparatively the contrary, craters few and far between. surface are separated most definitely from the seas, It has by being higher, more detailed, and to a great The question then arises, Which of these two so extent covered with crater-like forms. The seas, smooth, and widely diversified surfaces is the older? been supposed by some that the seas represent the more ancient state of our satellite, and that the crater-covered surface has encroached on them; yet this cannot be the case, for the shapes of the seas would then have been that of the spaces left between invading circular forms; but this is not the case; the seas tend greatly to circles, and press forward into the crater-covered surface with a fairly even line, broken occasionally by the remains under favourable circumstances, and of of partly destroyed craters. Mr. Green illustrated this point by drawings of Fracastorius, the ruins of the north wall of which he pointed out could be seen Doppelmeyer, Gassendi, and the Sinus Iridium. He also showed how the base of the Apennines appeared to be fringed by great masses of débris which seemed to have fallen from their summits. which is turned toHe then resumed: Thus far we have found that the These circumstances point lunar seas are comparatively a recent formation, that they increase in size from the limb towards the centre, and that in all probably they wards the earth: exist only on the side conclusively to some terrestrial influence in their formation, and for such influence we shall not have long to seek, as it will be found readily in the power of gravity and its tidal disturbances. Time was, doubtless, when the moon had an axial rotation, and when, in consequence of a semi-fluid state, the attraction of the earth raised upon her surface a considerable tidal projection. This wave, her rotation as a free movement ceased to exist. by friction and other retarding causes, eventually reduced the rotation, till at last the moon presented the most heavy side towards the earth, and liquid interior, in obedience to the powerful atThen came the formation of the seas. The still traction of the earth, welled up through every places, and, spreading on the surface, reduced it crack and opening, choosing, of course, the weakest again to the semi-fluid condition, where now it is to be seen in the various forms of these lunar seas. It need not be supposed that these irruptions rose to a higher level than the older crater-covered surface; but that the heated mass cut its way into the general surface which it undermined, and gradually reduced the fallen portions. An example of this may be seen on the eastern edge of the Apennines, near Archimedes. The possibility of this remelting process is evident from the frequent cutting of one

ENGLISH MECHANIC AND WORLD OF SCIENCE': No. 1359.

crater form into another, portions of the older
crater being thoroughly destroyed by the contact.

Mr. Alex. J. G. Adams said: The idea that, owing to tidal action by the earth, lunar seas exist upon the side facing us only, was not quite clear to him. Were we to assume a single tide alone? The effect of gravitation was the production of two tides in a line with the disturbing body, and he thought this state would apply to the moon. Moreover, whilst in no way detracting from the general hypothesis, and whilst fully allowing for cleanness at the disc edge, the probability of double tide carried with it the idea of seas upon either side the moon. The point of tidal lag had been touched upon and deserved further remark. Our tidal effects were always in rear of causation, and in some cases there appeared to be a harmonic give and take, as exampled by the fact that whereas the spring tides lagged more and more each spring lunation, the neaps gained, insomuch as to produce occasional overlapping. In the case of the moon, however, it was probable, owing to coincidence in her periods of orbital and rotative motions, that her tidal lag would be comparatively fixed, and seemingly just such as to produce decrease of sea upon her western limb.

Eighteen new members were elected, and eleven

candidates for election announced.

USEFUL AND SCIENTIFIC NOTES.

SCIENTIFIC NEWS.

HE Astronomical Congress begun its

APRIL 10, 1891.

or applied in combination with an adjunct such
as periodohymethyloxychinolin.
At a recent meeting the

the work of charting the heavens by photography tributed a paper on the proper odour of earth, in
Two, and is hoped that all the details of Sciences, MM. Berth oft alaris Academy of
will soon be settled.
Holland, Italy, Russia, Brazil, and Chili have origin of the odour which is so noticeable in a
sent representatives, while French astronomical garden after a shower of rain. The essential
Great Britain, Germany, which they described their researches into the
science is strongly represented. At an informal principle resides in an organic compound of the
meeting a programme was drawn up to be sub-aromatic series, its odour being very penetrating
mitted to the General Congress; but in the and analogous to that of the camphors. The
course of the discussions many points will new principle, which is neither acid, alkali, or a
naturally come up for settlement.
normal aldehyde, exists only in a very small
proportion in mould.

by him on March 30 will be close to the sun in
Aries towards the end of the present month.
Mr. Denning says that the comet discovered
He gives its position for April 11 as R.A. 1h. 38m.
N. Dec. 32°.

Douglas Bryce Douglas, managing director of The death is announced of Mr. Archibald the Naval Construction and Armaments Comoccupied a prominent position in the shipbuilding pany (Limited), at the age of 52. Mr. Douglas and engineering world. While at the Fairfield Shipbuilding Company's works on the Clyde he built some of the most powerful marine engines Arizona, Etruria, Umbria, and Stirling Castle. ever constructed, notably those of the Alaska, RICH deposits of phosphate of lime have been neer, but was also so much of a business man Mr. Douglas was not only a distinguished engidiscovered by M. Philippe Thomas, south and north that he acquired much influence in comof the high plateaux of Tunisia, from the Chotts to mercial circles, and was at the time of his Medjerdah. Those of the south-west are the death, engaged in perfecting an important most important, and will be very valuable when a scheme for constructing a line of steamers to railway has been run to them. It is estimated that cross the Atlantic to Canada in five days, and in the upland of Gafsa there are at least ten million another line to run from Vancouver to Australia, tons ready to be removed. The beds of the north-saving several days compared to other routes. east and the north-west also promise to repay exploitation. MAGNESITE, the new rival of barytes and other countryman who had been settled there for many Many English visitors to Florence will miss a similar articles in the manufacture of paints, con-years as a pharmaceutical chemist. tinues to excite interest among the whole trade. Groves was only fifty-six at the time of his death; The Chemical Trades Journal says this mineral, but during his residence in Italy he acquired a Mr. Henry being nearly 99 per cent. pure carbonate of mag- unique knowledge of the flora of Tuscany, if not nesia, at the same time very white, heavy, and of the whole of Italy. His collection of plants opaque, is, in addition to its usefulness as a paint, has become the property of the Central Botanical probably the cheapest form of magnesia for Society of Tuscany. chemists, and is very useful in many other ways in the arts. It is also used largely in Europe by Soap manufacturers to give weight and body to their cheaper grades.

gress will be held at Budapest from May 17 to The second International Ornithological ConCost of Aluminium. In a paper recently read Bethlen, the Hungarian Minister of Agriculture. 20, under the presidency of Count Andrew before the Massachusetts Institute of Technology, The Hungarian committee have made arrange Boston, by Mr. A. E. Hunt, of the Pittsburg ments for exhibiting in the museum specimens of Reduction Company, on "The Cost of Aluminium," it was stated that the probable cost of producing bition of poultry and pigeons, arranged by the the birds peculiar to Hungary, and also an exhialuminium upon a large scale would be:-21b. of Acclimatisation Society. The committee have alumina (Al, containing 52.94 per cent. Al) at taken steps that, for the convenience of the 3 cents, 0.06 dol.: 1lb. of carbon electrode at 2 cents, Congress, the results obtained in different parts 02dol.; chemicals, carbon dust. and pots, Oldol. of Hungary from practical observations of the 22 electrical horse-power exerted one hour (waterpower being used), 05dol.; labour and superin- passage of birds shall be graphically exhibited tendence, 03dol.; general expense, interest, and and explained, and they have provided facilities repairs, 03dol.; total cost of 1lb. of aluminium, for the members to visit those parts of the 0-20dol. The cost of aluminium at the works of country that are of most interest to ornitholothe Pittsburg Reduction Company, which have a gists, under the guidance of competent leaders. than this. The estimate is of value though, as interesting to ornithologists will be delivered. capacity of only 375lb. per day, is much greater During the Congress several lectures on subjects showing to what point the cost of producing aluminium may be reduced under present conditions.

An

The First Transatlantic Steamer. interesting correspondence has been taking place in the Canadian papers with the view of authenticating the claim of the Royal William to have been the

first steamer to cross the Atlantic.

At a recent meeting of the Royal Botanic Society the secretary brought to the notice of down in the gardens, showing a network of roots members a portion of a large poplar lately blown running almost round the trunk, between the William was built in Quebec in 1830-31, and ground. The plant had apparently derived its The Royal bark and wood, at some distance from the engined at Montreal. She traded at first between nourishment, not from the soil, but from the the last-named port and Halifax; but in 1833 was decaying portions of itself. sent across the Atlantic (doing the voyage in 21 days), and was sold at London to the Spanish Government, Captain M'Dougall, the master, being

Durham College of Science, the college authoriAgriculture and forestry are to be studied at the tics having acquired 15 acres of land near retained in command for several years. Goudie, under whose direction the vessel was built, James is now 81 years of age, and has recently written a William Somerville has been appointed to the Gosforth for an experimental station. letter to the Montreal Gazette. Dr. although the American ship Savannah crossed with for teachers will form portions of the programme. He states that chair. "Extension lectures" and special classes the aid of steam in 1819, 14 years before the Royal William, she was a full-rigged packet, built for a sailing ship, that her engines were auxiliary and been studying the properties of Papaw juice, and Dr. Mortimer Granville has for some time only used in fine weather, and that the owners, he believes that in it he has discovered a possible having tired of the experiment, gave it up. Mr. remedy for cancer when used with some other Goudie says that the Royal William was built for a preparations. The Papaw is the Carica Papaya, sea-going steamship, and that "he never had the and its juice has long been known to possess the slightest idea of her failure to reach London as a remarkable property of softening flesh, and the sea-going steamer," and further, that she was leaves are often used by the natives of Tropical actually the first steamship to fire a gun in action, America to render meat tender by wrapping it in which is something of an honour for Quebec." the register of the Royal William, George Black is named as the builder of this vessel, which was them. The organised ferment of the Papaw propelled by steam with wheels, or flyers, at each Granville says that he has satisfied himself of the juice is believed to be a bacillus; but Dr. side.' She is designated on the register as belong- therapeutic value of the juice, or certain if its ing to the Incorporated Quebec and Halifax Steam elements, as Navigation Company. a solvent indurated tissues in cancer, when administered of the morbifically

66

In

Crosskey will lecture on the "Extinct Volcanoes
of France."
At the Royal Victoria Hall, on April 14th, Dr.

Biological Association from £500 to £1,000.
proposal to increase the grant to the Marine
The estimates for the year 1891-92 contain a

in large cities, found that some of the mud and hygienic character of the surface of the streets Signor Manfredi, who has been studying the bacteria that it might be compared to sewage. The most frequently found bacilli are those rubbish scraped up in Naples was so rich in recognised as specific to tetanus, edema, and

tuberculosis.

M. Gessard obtained both pyocyanin and green fluorescence; on egg albumen, after a time, the By growing the pyocyaneus bacillus on bouillon green fluorescence is lost, while on gelatinised peptone infusions of meat pyocyanin is produced, but not the green fluorescence.

Flies have long been accused-not without
for if they inoculate anyone after biting a yellow-
reason-of spreading disease; but it is asserted
now from Havana that mosquitoes have a use,
that fatal results are rare.
fever patient, the disease which follows is so mild

brewers, gives a method of detecting sulphured
hops which may be useful in other ways. A
knitting-needle is fitted with a silver-plated
A German paper, devoted to the interests of
three hours the silvered knob is blackened, the
leave only the knob visible.
knob and is driven into the bale of hops so as to
If after two or
sulphuring of the hops is considered to be proved.

will be delivered by Dr. Karl Pearson, and will
be on the geometry of motion, matter and force,
The Gresham lectures on April 14, 15, 16, 17
and the classification of the sciences.

possible to drive a coach and four through an
Act of Parliament, it is impossible to drive a
steam or electric cycle through the Acts which
It is pointed out that, although it may be
form the law governing traffic on the highways.

France, by which vessels could pass from the
Bay of Biscay up the Gironde to the Mediter
The proposal to construct a ship canal through
ranean, was abandoned on account of the cost,
but a committee has, it is stated, been formed at
structing a ship railway.
Bordeaux to inquire into the feasibility of con-
280 miles.

The distance is about

to run to Aberdeen in 12 hours and 5 minutes, or The North express leaving Euston at 8 p.m. is occupied in reaching Perth, a shorter distance by about the same time that a few years ago was about 90 miles. Aberdeen is about 540 miles

from Euston.

remarkable series of entries in her log for the return to this country the other day, showed City of New York, on he previous outward trip-four days' runs readin respectively 502, 501, 500, and 503 knots. N steamer has ever made 500 knots on four day during one voyage. Is the performance due

the twin screws?

Society will be held on the 15th inst., at 8 p.
The next meeting of the Royal Microscopi
at 20, Hanover-square,
Rotifera,
papers will be read:-(1) On New Forei
the followi
R.N.; (2) "An Additional Note on the Tre
by Surgeon V.
Gunson Thor
C. Haughton Gill, F. C.S.
ment of Diatoms by Chemical Depositions,"

PRIL 10, 1891

ENGLISH MECHANIC AND WORLD OF SCIENCE: No. 1359.

ETTERS TO THE EDITOR.

lave do not hold ourselves responsible for the opinions of rrespondents. The Editor respectfully requests that all unications should be drawn up as briefly as possible.] communications should be addressed to the EDITOв of IGLISH MECHANIC, 332, Strand, W.O.

Cheques and Post-office Orders to be made payable to

SSMORE EDWARDS.

In order to facilitate reference, Correspondents, when fing of any letter previously inserted, will oblige by ming the number of the Letter, as well as the page on it appears.

would have everyone write what he knows, and as 2. as he knows, but no more; and that not in this but in all other subjects: For such a person may some particular knowledge and experience of the e of such a person or such a fountain, that as to things, knows no more than what everybody does, et, to keep a clutter with this little pittance of his, ndertake to write the whole body of physicks, a vice whence great inconveniences derive their original." taigne's Essays.

THE PERSEID RADIANT.

2212.]-Ir will be evident to all meteor obrs who have given much attention to their observed meteor-paths and in assigning them keir radiants, that Mr. Monck's criticisms are of one feature, and that is the observational I am obliged to say this in response to his got from Plassrks respecting the radiants 1's observations. Mr. Monck says "there are, nk, several reasons for not laying too much lea on them. In the first place, Mr. Booth es that they give a diffused, not an accurate, nt." It is in this last sentence where Mr. ek shows his want of the practical part. I ed inform him that the change in the centre of tion means also that the diffusion moves along e same rate as the centre, the diffused area ng about the same diameter in all cases. David Booth. North-street, Leeds.

GLACIATION OF THE MOON'S

SURFACE.

sun!

viewed him thus:-"Well, John, I hear you had a
grand view of the sun yesterday: I have often
heard it said that it dances on Easter Day, but
"Aa, sir, it was the grandest sight as I ever see in
never met with any one who had really seen it."
my life. It kep' on the dance for nigh one hour-
Nobody couldn't form no idee as hadn't seen it.
and-half, dancin' an' turnin' round all the time.
it kep' dartin' out, dartin' out light, it did. It was
It was like as if it had cogwheels all round it, and
most like that thing in the Menagic Lantern as
a sketch [view] on it ever sin' my mother told me,|
keeps turning round. I've been very anshus to get
an' she's been dead this 14 years. I seed milkman a
an'
'Bless my life,' he says, I never see nowt
goin' past, an' I calls out, Look at that there
to look at it. The sun rose bright this
like it.' Then I goes an' calls up Mrs.
Mary
Such is faithful John's story. I am certain, from
morning, but aa! it was as different as it could be."
unlike any other sunrise he ever saw and he sees
his manner of telling it, that he did see something
it every day. It would be interesting to know
whether there was any actual phenomenon ob-
servable, which would account for his being im-
pressed as he was with a deep feeling of mystery
I know, of course, that you will "put your foot
and wonder.-I am, &c.,
very sternly on any attempt to drag in
down"
theology in this connection, and I disclaim any such
or any other well-informed correspondents have to
intention. All I want to know is what" F.R.A.S."
D. C. Grant.
say as to the possible causes of the illusion which
the Lincolnshire peasants fancy they witness on
Easter Day.

that all

C. E. C.

THE DISSIPATION OF ENERGY. [32215.] As "O.T.O.H.P." (letter 32204, p. 116) asks for opinions on the above, I venture to Some four years ago I published a small pamphlet send him mine. on "The Mystery of Gravity" (which, I am happy to say, was favourably noticed in this journal), in which I gave, in my opinion, good reasons to show energy went to form the dissipated force which we call gravity. In it I point out that all the bodies in the uni213.]-I THINK "F.R.A.S." has somewhat prehended my formulation of the circum-verse must be vibrating in unison with the zero es attending a supposed uprush of gas, carry- temperature of space-with star heat, in fact and with it particles of solid matter, to form a misty that consequently the lowest form of heat-waves of limited extent on the surface of the moon. I must be able to pass through them without refor a moment supposed that gas could return flection; that they are absorbed, conducted, and sno pressure to pressure, but I suppose I must radiated almost as if the atoms of the bodies written with insufficient distinctness: I say through which they passed formed part of the ald again return to the interior as the force was etherial medium. I point out that they would pass ded," and would it not do so? as I presume through all bodies with the same velocity as through that force would be heat, and as the heat was the ether if the bodies were not sheltered by each ated through the vent, the interior would be other from the influence of star heat; but as they d by that expenditure of heat, and the gas are more or less sheltered, so will the heat-waves be d contract into the aperture, even it it had in more or less interrupted in passing through, and so Enean time become diffused to some distance be made to part with more or less of their energy ad, if there was no layer of gas permanently on to every atom of the mass through which they temperature. urface, and if there was such a layer, and the pass; sheltering, of course, causing a lowering of shed gas was diffused in the surrounding gas, ame quantity of gas would subside into the Sure under the influence of gravity on the coolaking place.

and so enable me to see it.

. S. E. Peal (32198) formulation 7, says: at from these orifices a haze or cloud is ced, seems not to be disputed." ould Mr. Ranyard examine the photo of the noon by Rutherford in "Proctor's Moon," and if the northern limb, where there is little ation of mountains, is not much brighter than Southern, where the mountains are distinctly to en covering the surface, and how does this agree his theory that that brightness is caused by the ntain tops being lighter than the general

ace.

letter 32200, 32in. apparent diameter should be
(of arc). (I hope I have made my meaning so
that "F.R.A.S." can understand.)
S. Broughton.

energy.

This is the barest outline of my theory; but if
"O. T. O. H. P." cares to read it, I shall be only too
happy to forward him one of my pamphlets free, if
little book has scarcely sold at all, perhaps owing to
he will send me his address. I may say that my
the want of pushing; in fact it was a little weak in
ous action of gravity, and partly on that account I
that part which tried to account for the instantane-
"E. M." would like, and our Editor does not
accounted for that fact, and if the readers of the
did not care to push it; but since then I have fully
Danby Wiske, Yorks, April 5.
ENGLISH MECHANIC.
object, I shall be very happy to publish it in the

NECESSARY
MANGANESE
CELLS OF THE LECLANCHE TYPE?
[32216.]-THIS subject, introduced by T. H.
Nash (letter 32193), is not a new one. It was well
gone into in the "E.M." for 1882.

If those interested will refer to page 332, Vol.
XXXV., a letter will be found from "Arch Key,"
where he gives the results of the working of two
sets of cells, one lot containing carbon and man-
set up on May 1st, and worked under exactly
ganese, the others crushed carbon only. Both were
similar conditions. Upon testing on May 22nd, the
was exactly double of those not so fitted with the
E.M.F. of the set containing manganese and carbon
19 was led to make these
Arch Key
perfectly.
mixture. On June 5th the set without the man-
hampton describing (on page 61) a cell of his own
design, where he used three carbon plates arranged
ganese failed, whereas the others still worked
in a triangular shape, with crushed carbon only
experiments through Mr. Tolman of Wolver-
on the outside, the zinc rod being in the centre.
The same gentleman, on page 352, details his
and carbon, yet far from satisfactory.
troubles with cells well supplied with manganese

The most explicit reasoning concerning zinc
on Batteries," pages 72 to 75, where mention is
carbon cells is to be found in "Niaudet's Treatise
viz., a tall porous cell, in
made of a cell exactly similar to that suggested
by Mr. Sprague in the second edition of his
"Electricity"
which is placed a carbon rod surrounded with
crushed carbon only; but he well remarks, "this will
only serve for short demands upon its service." For
my own part, I cannot see any reason for leaving
the manganese out of the carbon mixture: its cost
is not heavy, and I am certain of this-however
well a zinc-carbon cell acts without the addition of
manganese, my own experience tells me it works
much better with it. The Electrical Review has
commented on Mr. Nash's letter in this week's
issue, so if he has any further reliable information
John J. Gilbert, A.I.E.E.
to give, I hope he will do so, at the same time
stating if his carbons were lead-capped or plain,
King's Heath, April 4.
because I have always been troubled with the
carbon connections in these cells.

132217.]-I WAS very pleased to see a letter in the "E.M." from T. H. Nash, p. 98, No. 1357 on "Is Manganese Necessary in Cells of the Leclanché Type?" (letter 32193).

A short time ago I put a carbon, 12in. by 44in., with salammoniac, and in a few days the current in a stone jar 10in. high about half-full of water stopped. The zinc was a piece of thin sheet of ways to get a current, but failed to get enough to large size folded up, amalgamated. I tried various ring a bell. I then took a new piece of carbon, much smaller, and put into cell, and at once got a on it, and put about lb. of manganese on it, wrapped good current from it. Not knowing what to do for the best, I took a piece of bagging, laid large carbon it up, tied it, and replaced in cell; there has been a good current up to the present.

I shall be glad if some one will kindly tell the W. M. reason of this. The carbon I used was a rough piece with just the loose surface scratched off.

There will thus be a pressure on all bodies sheltering body, and inversely proportional to the I point out that the heattowards each other, directly as the mass of the ery much regret that I had not the oppor- square of distance. y of hearing Mr. Green's paper on the evidence waves, in their progress through space, must, in point out that, in an infinite universe, e existence of water on the moon; but per- the course of time in an infinite universe, come into it may find its way into some of the publica-contact with some body, and so part with their owing to the uneven distribution of heated masses is weak, or even where it has no existence, and that in space, there must be some parts where gravity consequently there must be a "drift" of bodies from spaces where gravity is strong towards the I believe our sun and all his spaces where it is weak or has no existence. (I consider "star drift" to be the result of ages of "dissipated energy." planets to be drifting towards a portion of space where the force of gravity is weaker than in the former portion will be greater than towards the opposite portion; hence the pressure towards the AMATEUR BOOKBINDING. the bodies in that portion of space must part with latter.) I point out that, in the course of time, in any very large, but not unlimited portion of space, their heat, and that consequently the temperature [32218.]-I WAS much surprised to see in the of all parts being alike, the shielding of one body by "E.M." of March 13 a letter from "G. R. J. P." another will make no difference in their temperaBodies in cially when he says, "which were quite equal to "DANCE ON EASTER tures, and in that part of space gravity can have no existence. What would happen in a gravitation-advocating cutting book-edges with a chisel, espeDAY"? 2214.]—I SHOULD be ashamed to trouble any of less universe can easily be imagined. "G. R. J. P.'s" plough must have astronomical correspondents with this ques-rotation would fly to pieces, while all would fly off books which I have since cut with a plough." I but the Spectator-a journal at least, generally in straight lines, with the result that chaos would have tried both plans, and although my plough king, the equal of "Ours" in sanity, though come again, and, in process of time, the old fires is only a home-made affair, if I had to revert to also is by occasional cranky would, owing to collision, be relighted, and solar the chisel, I should be tempted to give up my hobby "Ours" ted as espondents of the "E.L.G." and other similar and sidereal systems be evolved a fresh, and so on in disgust. would be at a minimum, while molar energy would uasions, thinks it worth putting, judging from for ever. According to this theory at the time been a badly-made one, or he had not got into the following letter, which appears in the last when gravitation would be nil, molecular energy knack of using it. B,-Folk-lore dies out fast; let us cherish what be at a maximum. After collision, and the relightIt is still firmly believed in Lincoln- ing of the old fires, molecular energy would be at a e that the sun dances on Easter Sunday in maximum, while molar energy would be at a our of our Lord's resurrection. Having heard minimum. There would be an incessant change of E my gardener (as honest and as excellent a the forms of energy, from molecular to molar, and colnshire man as is to be found) had looked out from molar to molecular, no loss of energy being the phenomenon and seen it this year, I inter- possible.

ES THE SUN

remains.

I would strongly urge all who are making a hobby of bookbinding to become possessed, by hook or by crook, of a plough; they are rather smith, and, for a few coppers, got him to cut it into expensive to buy, but almost any joiner or cabinetmaker ought to be able to make one if he had a sketch to go by. As for the knife, I picked a lawnmower-blade off a scrap heap, took it to a black