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SCIENCE OF FAMILIAR THINGS:
SIR NORMAN LOCKYER ON THE TOTAL SOLAR ECLIPSE IN BRITISH
INDIA (JAN. 22, 1898), AND ON THE ECLIPSES OF 1793 AND 1896.
y the time the present number spread than it is now, superstition, fear,
of SELF CULTURE reaches the and dread put all other emotions in the hand of the reader, it will shade." And so impressed has he been doubtless be known what suc- by the awe-inspiring experience of six
cess has attended the expedi- eclipses, that the utmost he can do - and tion to British India, sent out from he could not have done better — is to England by a joint committee of the quote Professor Grant's quite genuine, if Royal and Astronomical Societies, to re- slightly old-fashioned, eloquence on the port upon the total Eclipse of the Sun, subject of an eclipse written forty years which is to take place on the 22nd of ago:January. Apropos of the occasion, Sir "On no other occasion does the display of Norman Lockyer, professor of astro- stupendous power in the economy of the phynomical physics at the Royal College of
sical universe exercise so subduing an influence Science, London, and the learned author
over the mind, or produce so humiliating a
conviction of the impotence of all human efof many valuable treatises on astron- forts to control the immutable laws of Nature omy, has issued a timely volume deal- and arrest the course of events, as when the ing with "Recent and Coming Eclipses"
glorious orb of day, while riding in the heavens
with unclouded splendor, begins to melt away (London and New York: Macmillan and
froin an unseen cause, and soon totally disappears, Co.). The work chiefly consists of notes leaving the whole visible world wrapped in the on the total solar eclipses of 1893, and sable gloom of nocturnal darkness. The scene 1896, with hints to govern the expedition
is rendered still more impressive by the circumnow on its way to India. An interest
stances accompanying so remarkable an occur
rence. The heavens assume an unnatural aspect ing account of the volume recently ap- which excites a feeling of horror in the specpeared in the London “Spectator," from tator; a livid hue is diffused over all terrestrial which we make the following extracts.
objects; plants close up their leaves as on the Sir Norman Lockyer, says the re
approach of night; the fowls betake themselves
to their resting-places; the warbling of the grove viewer, is not only an eminently prac- is hushed in profound silence; in other words, tical but a thoroughly practiced astron- universal Nature seems to relax her energies, as omer; yet he is happily one of those
if the pulse which stimulated her mighty movescientific men who do not regard as
ments had all at once stood still." mere sentimentality the emotions that
Yet, although Sir Norman Lockyer are encouraged, if not evoked, by the professes to be unable to describe his own familiar mystery of Nature. The book feelings better than by quoting Professor which he has published is composed
Grant's words, he thus himself breaks out mainly of the actual observations of
when describing the eclipse of 18715 astronomical phenomena, but the mak- “There in the leaden-colored, utterly cloud. ing of these has not expelled from his
less sky shone out the eclipsed sun-a worthy
sight for gods and men. There, rigid in the mind what the late Laureate would have
heavens, was what struck everybody as a decortermed his “cosmic pantheism," - that ation - one that Emperors might fight for, a feeling which perhaps finds most adequate
thousand times more brilliant even than the expression in the divine simplicity of
Star of India, where we then were! A picture “The heavens declare the glory of God.”
of surpassing, loveliness, and giving one the
idea of serenity among all the activity that He opens his first chapter which bears
was going on below; shining with a sheen as of the title of “Eclipse Revelations and silver." their Uses,” with these words: “There As has been hinted, this book is emiis no question that a total eclipse of our nently “practical.” For one thing, it central luminary is one of the grandest gives in detail the elaborate preparations and most awe-inspiring sights that it is made, with, however, but imperfect sucgiven to man to witness; feelings of awe, cess, for observing in Norway the great mingled with vonder, areat once appealed eclipse of August 9, 1896. For anto by the attendant phenomena; and it is other, it explains at great length the not surprising that in ancient times, when achievements in the way of eclipse obserknowledge was less, and less widely vation that have been attained by means
of the prismatic camera and the spectro- thereby an additional proof of the advantage to scope. It is four years since the large
us of the short nights. There is no time either
for any considerable reduction of temperature scale prismatic camera was introduced:
or for the accumulation of any great amount of “The results obtained by large-scale pris
moisture in the air.
I am glad to say matic cameras showed everybody that these
that the last adjustments have been made, the instruments were the most important ones we
last demonstrations given; numerous rehearsals can employ on an eclipsed sun. They not only
have landed us in the perfection of drill; the give us a complete chemical record on a scale parties all know their stations and all necessary hitherto undreamt of, but they give us the posi
forms have been written out. We are going tions and forms of the prominences far better
then to-day to 'stand easy,' and take some rest than these have ever been obtained before. in preparation for the fateful to-morrow." Nor is this all; they enable us to study under
The portion of Sir Norman Lockyer's new conditions some of the conclusions arrived at in previous eclipses, and give us a means of
book in which the failure of the expediinquiring into the possible origin of some of the tion of 1896 is described is, nevertheless, phenomena already recorded by slit spectro- very interesting for the amount of enscopes."
thusiasm in the scientific venture which Again, “the results obtained in that seems to have been aroused by it in the year (1893) represent, therefore, only the breasts of Captain King Hall and the experimental stage; at the critical mo- officers and men of the 'Volage.' When ments of the eclipse - that is, at the the Captain condoled with the leader of the beginning and end of totality - only expedition on his failure in attaining his snap-shots were taken. In 1896 what is main object, the latter replied that a most termed a dropping-plate was introduced important discovery had been made, that, in the programme of the prismatic camera, "he had demonstrated that with the minia plate being exposed, while gradually mum of help, and that chiefly in the falling, from ten seconds before the end matter of instruments, such a skilled and of totality to fifteen seconds after, in the enthusiastic ship's company as his could hope of catching the so-called 'flash, be formed in a week into one of the most which is supposed to represent the 're- tremendous engines of astronomical reversing layer,' which 'flash,' of course, search that the world has ever seen; so is simply the spectrum of the chromo- that if the elements had been kind all sphere.” It may seem to the ordinary previous records of work at one station and essentially unscientific reader that would have been beaten.” When Sir Sir Norman Lockyer devotes too much Norman asked for volunteers to help of his comparatively limited space to the him and his scientific associates in prismatic camera. But it should be re- their work, as many as seventy of the membered that, unaffected by the defeat men of the 'Volage' came forward, and of 1896, he is looking forward to a pos- they proved not only so willing, but so sible success in India on January 22nd capable, that he entrusted to one of the of this year. Whether that success,
bands into which the seventy were difrom being a possibility, will become a vided the charge of a very delicate in- . reality, must depend not a little on the strument. His experiences, indeed, seem further improvement of the machinery to suggest the desirability of our finding and processes upon which Sir Norman new fields for the energies of sailors, as lays stress.
well as of soldiers, in times of peace. The expedition of 1896 to Norway in As it is our chief purpose to point out H.M.S. 'Volage' to see the eclipse ended, the more popular features in this book, as it is unnecessary to recall, in disap- we merely commend to the attention of pointment; the eclipse was eclipsed by the specially interested Sir Norman Lockthe elements. Yet Sir Norman tells the yer's chapters on "The Chemistry of the story of failure very cheerfully; no doubt Sun as Determined in 1893 and 1896," he does wisely in republishing the letters “The Spectrum of the Corona," and which he contributed to "Nature" on “The Structure of the Sun's Atmothe subject, - although he must have a sphere.” The two final chapters deal Tantalus-like feeling of disappointment with "The Approaching Total Eclipse when he re-reads these words, written in India” and “The Work to be Done from Kio Island on the very eve of the During the Indian Eclipse." It is satiseclipse:
factory to note that in the meantime all “A lovely morning. The sun remained un
promises well for the eclipse of January clouded till long after eclipse time, giving 22, 1898. Sir Norman Lockyer, who
evidently bases quite reasonable hopes tour-conductor, “that India in the cool on a note drawn up on the climatic and season is reached over tranquil seas, and other conditions of Northern and Central presents one of the finest climates in the India and the Deccan, in which the eclipse world, to say nothing of what Nature will be observed, comes to the conclusion provides in the way of tropical scenery, that light northeast winds, fine weather, and successive dynasties have left behind and smooth seas are to be expected. Mr. them in the way of monuments, which Eliot, Meteorological Reporter to the are among the wonders and delights of Government of India, says positively: the world.” The Joint Committee of “The weather is throughout the month the Royal and Astronomical Societies of January almost uniformly fine, with have since the publication of this book clear or lightly clouded skies over the revised certain of the arrangements they whole of the peninsula. Light north
Light north- originally made, and it is to be hoped easterly to easterly winds obtain in
obtain in that neither pestilence nor "scare” will the Deccan or interior of the penin- upset them. Sir Norman Lockyer resula. The West Coast districts are pro- calls the success of the observations contected by the West Ghats from these ducted in 1871 in India, and anticipates winds, and light land and sea breezes greater success in January 1898 because, prevail.”
among other reasons, eye observations The Asiatic Society of Bengal has done have now been almost entirely supera good deal in the way of collecting and seded by permanent photographic recdisseminating information for the guid- ords. Sir Norman concludes a most ance of those visiting India on the occa- interesting and valuable book with a sion; "and be it not forgotten,” says chapter for scientific experts on “The Sir Norman, almost with the air of a Work to be Done."
COMMENT ON A CORRESPONDENT'S QUESTION, AND REPLY.
be zero and its easterly velocity will be 1,000+ I have been interested in the correspond- miles per hour. It will, therefore, for a very ent's question," on page 285 of your December small time, travel nearly parallel to the earth's number, concerning the action of a cannon ball surface (though it would appear to fall straight dropped from the surface of the earth, the latter down, because the earth's surface is also travel. being supposed to be permeable. While your ling); its velocity due to gravity will gradually answer is correct if the ball were dropped from increase, while the force due to gravity will de either pole of the earth, it would hardly be so if it crease, the centrifugal force of the ball itself inwere dropped from any other point. If, for in- creasing, until, as explained above, the two latter stance, it were dropped from any point upon forces balance each other and the ball ceases to the equator, it would have an easterly velocity move towards the centre. The velocity due to of over 1,000 miles per hour before it started to gravity will now decrease; its original velocity fall, due to the earth's rotation. At the surface will change its direction in space, though its of the earth it would make one revolution per easterly direction, relative to the earth, will not day; but as its linear velocity due to its original change, and the ball will be moving away from motion would be constant, the number of revolu- the earth's centre. tions which it would make per day would be It will reach the surface of the earth nearly inversely proportional to its distance from the opposite its starting-point, the time of its travel earth's centre, i.e., when it was 2,000 miles being the same as if it had fallen straight from the earth's centre it would make two rev- through. I say “nearly,” because while it was olutions per day, and when it was 1,000 miles travelling from one point on the surface to the from the earth's centre it would make four rev- other, the surface of the earth itself would have olutions per day. This does not consider its moved 700 miles to the east, and the ball would velocity due to gravity.
therefore be 700 miles west of an opposite point. The linear velocity of the ball would increase The ball would then start in a curved path as it neared the centre, due to the action of towards a point 1,400 miles west of its original gravity. The centrifugal force of the ball, tend- starting-place and would pass on the opposite ing to throw it away from the centre of its rota- side of the earth's centre from its first path. tion at any instant, would increase as the square The sum of these rather complex motions is of its velocity divided by its distance from the that the ball would describe a set of elliptical instantaneous centre of its curved path. As the spirals, on a plane cut through the earth at the centripetal force of gravity would decrease as equator, the axis of which would make one revthe ball neared the earth's centre, it is plain olution every twenty-four hours. If the path that a point would be eventually reached at were not relative to the earth, but were an absowhich the two forces balance, and the ball would lute path in space, it would be but a single ellipse cease to move towards the earth's centre.
which would be closed, and the earth would make Tracing the path of the ball, we find that as its ordinary daily revolution, relative to this it starts to fall the velocity due to gravity will ellipse, as it is also relative to absolute space.
With this latter modification, and one due to Incidentally, mention was made of the the fact that gravity varies inversely as the effect of striking a swinging pendulum, square of the distance between the centres of the two bodies concerned, instead of directly as
when at the end of its swing, in a directhat distance, as in the case just considered, tion perpendicular to the plane of its the phenomenon, barring air resistance, would oscillation, namely, the giving of it an be exactly the same as is exhibited when a
elliptical movement. Let our imaginary comet, with an original velocity not directly towards the sun, comes into the solar system.
cannon ball, instead of dropping from a As we have seen, it would approach the sun state of rest, have at the start an eastuntil the centrifugal force equalled the centrip- ward movement of five miles a second, etal force, when it would commence to move
and it will go round the earth, instead of away from it, in a path either elliptical or parabolic. It is this same balancing of forces that
through it, moving in a circle. Let its keeps the earth in its elliptical path, and pre
initial velocity toward the east be 1,000 vents it from falling into the sun. The law is miles an hour-five-eighteenths of a mile the one expounded by Newton in proof of his
a second — and it will move in an ellipse, hypothesis of universal gravitation. I will say, in closing, that I look forward
the longer axis of which will be the with pleasure to every number of SELF CUL- earth's diameter, or 8,000 miles; the TURE, and consider every number a part of my shorter, one-eighteenth of this distance, education. By educated people, on all sides, I or 444 miles, about. This would be the hear it spoken of in the highest terms. Personally, I simply could not get along without it.
case in Mr. Taylor's problem of a “perIRVING A. TAYLOR.
meable" earth. As Mr. Taylor has BROOKLYN, N. Y., Dec. 18.
said, the axis of the ellipse would have
a fixed direction in space, while the earth The writer of the above letter is right would rotate with reference to it. Mr. as to what would happen to a cannon Taylor is in error upon one point, howball dropped from the surface of the earth
ever. The movement of the ball would “the latter being supposed to be permea- not be analogous to that of a comet or ble" - to offer no resistance to the move- of any other celestial body. In celestial ment of the ball. But this was not the
mechanics the attracting force varies supposition made in the question which
inversely as the square of the distance SELF CULTURE answered. Clearly a ball from its centre varies, and this centre is could not move in the manner described always found at one focus of the orbit by Mr. Taylor, were it confined within of the moving body. In the case above the limits of a “hole passing through the supposed, the attracting force varies diearth's centre." Actually a ball dropped rectly as the distance of the moving
” into a very deep perpendicular hole in body from the point of attraction, and the earth would strike the eastern side at this point becomes the centre- not one no very great depth, would glance to the
focus of the ellipse which the body western side, then to the eastern, and so describes. on, as it descended more and more rapidly,
GEO. SENECA JONES. and the consequent friction would be one source of the resistance it would encounter in its fall, another source being the atmosphere. If the hole passed clean The discovery of a large bed of strontium at through the earth, the result would be
Put-in-Bay Island, reported from Toledo, has
awakened a considerable amount of interest as SELF CULTURE stated; the ball — or its fragments — would finally, after re
among the manufacturers of fireworks, as it is
thought likely that it will result in a considerapeated oscillations to and fro past the
ble reduction in the price of all fireworks in earth's centre, come to rest at that point. which strontium nitrate or strontium carbonate
In answering the question an imagi- is used. One large manufacturer of fireworks nary case was considered, in which there in New York, who makes use of about one hunwas no resistance, the body being sup- dred and fifty tons of strontium nitrate in a year posed to start from a state of rest and to and imports the whole of it from Europe, states be acted upon only by gravity, the effect
that it costs his firm now about seven and a of gravity being, obviously, the matter
quarter cents a pound. If the strontium should
be found in large quantities, it would have the about which the questioner was in doubt.
effect of lowering the cost of certain classes of The answer given that the ball would
fireworks, that is, all those that use a red or under these circumstances move essenti
crimson light. At present the supply comes ally as a swinging pendulum, was cor- chiefly from Germany, and the American manrect.
ufacturer has to pay a high price for it.
o vary the interest in these series of questions, as well as to increase the
educational benefits arising from their daily study in tracing them to the sources of the history, it is designed, for awhile, to group the ques. tions under specific countries, and to withhold reference to the pages in
the Britannica, or in the New Supplement thereto, where the answers may be sought. In the present series of questions (for the month of February), it may suffice to say that answers will be found either under the general article on England, in the E. B., or under that of the separate British colonies or specific events referred to in the questions.-ED. S. C.
ENGLAND AND HER COLONIAL HISTORY
Feb. I. Give a list of the British Colonies Feb. 16. England owns or exercises a proand foreign possessions throughout the world, tectorate in equatorial and Southern Africa over describing the situation of each.
an area of two and a half million square miles. Feb. 2. Indicate the chief trade routes be
Name the colonies, possessions and territories tween Great Britain and her colonies, naming
within this area; state, approximately, its ex
tent of seaboard. the principal ports of these colonies. Feb. 3. Name ten of the more important
Feb. 17. Of what colonies or possessions of fortified naval depots of Britain in foreign England are the following towns the capitals: waters, and indicate their situations.
Victoria, Fredericton, Brisbane, Hobart, Well
ington, Kingston, Georgetown? Feb. 4. State how England came to acquire her possessions in the Mediterranean and the
Feb. 18. What are the chief provisions of Levant.
the British North America Act, and when was Feb. 5. Name the principal British Islands
it enacted ? in the West Indies, and state when and under what circumstances they were acquired.
Feb. 19. Name and give the position of the
chief seaports of the British Isles, and locate on Feb. 6. Trace the progress of British con- a map the following towns: Canterbury, Portquest in India from Clive's day to the close of
land, Sunderland, Roscommon, Dumbarton, the eighteenth century.
Drogheda, Inverness, Brighton. Feb. 7. Name the causes which led to the Feb. 20. What possessions did England gain British conquest of Canada, and those which by the treaty of Vienna? Give the date of the led to the separation of the American Colonies. treaty.
Feb. 8. What were the grievances of the Feb. 21. Give the date of the abolition of people of Canada which led to the Rebellion of the slave trade in the British dominions, and 1837 ?
name the sum granted the owners as compensa
tion for their slaves. Feb. 9. Name the seven provinces that constitute, with the partially organized territories, Feb. 22. When was the government of India the Dominion of Canada, and give their capitals. transferred to the British Crown?
Feb. 1o. Give the total population of the Feb. 23. When was telegraphic communicaprovinces and native states of British India, and tion between this country and England finally indicate, approximately, the religious persuasion established ? (Hindus, Mohammedans, Buddhists, etc.) of the people of the Indian Empire.
Feb. 24. Give the dates and the assigned Feb. II. When did China cede to England
causes of the Abyssinian and the Ashantee
wars. When did the Maori war in New Zealand her Crown Colony of Hong Kong, and how are
close ? its affairs administered by England ? Feb. 12. How and when did Ceylon fall
Feb. 25. In what year was a Roman Cathounder British rule, and when did England pro
lic hierarchy re-established in England? Give claim a protectorate over North Borneo ?
the date of Catholic Emancipation. Feb. 13. Give the dates of British settlement
Feb. 26. When was the Oregon boundary in the various Australian Colonies, and state dispute settled between this country and Engwhich is the oldest colony.
land ? Feb. 14. When did Britain obtain, by native Feb. 27. When, and for what territorial comtreaty, possession of New Zealand, and when pensation, did England cede Heligoland to was self-government granted to the colony? Germany?
Feb. 15. What commercial advantages has Feb. 28. What did Jay's Treaty accomplish Britain gained from her recent acquisition of in the adjustment of differences between the Upper Burma ?
United States and England ?