Rodolfo Amedeo Lanciani.

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very least, than the brightest, and the different stars altogether too
far apart to exert any influence on each other. Indeed, whatever
theory we may hold respecting stellar distribution, regarded gene-
rally, we must be prepared to recognize in the stars seen toward
any part of the sky, objects which lie at very different distances.
And regarding these objects as severally in motion, we must be
prepared to find in general the utmost oiversity, not only as re-
spects the direction of the apparent motions oif the stars, but
also as respects the magnitude of these motions. It is only when
one has adopted the theory that the stars are grouped according
to special laws of aggregation, that one would be led to anticipate
that here and there, almost as by accident, so to speak, some indi-
cations of their grouping might be discoverable in the characteris-
tics of the stellar proper motions. Although I had become firmly
convinced that the stars are not distributed throughout space with
any approach to that general uniformity insisted on oy many
astronomers, I had very little hope that a suggestion I threw out
a year a^o in the pages of the Student^ that the stellar proper
motions if examined carefully might afford evidence in favor of
my views, would be confirmed in any very distinct manner if the
method I had pointed out should ever be applied. I knew that a
certain conmiunity of motion in the constellation Taurus had led
M&dler to important, but as I judeed incorrect conclusions as to
the nature of the stellar motions ; but I also knew that that com-
munitv of motion was one which could only be appreciated by the
few wno had convinced themselves of what was to be expected if
the stars were uniformly distributed. I had an impression at that
time that M&dler had examined the stellar proper motions over



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Astronomy, 487

the whole of the northern hemisphere, and that it was the excep-
tional community of proper motion in Taurus which had led him
to form his well-known tneory respecting a central sun. It was
only when I was reminded that he nad in fact examined the stellar

{)roper motions in the neighborhood of Taurus alone, having been
ed by independent considerations to regard that neighborhood as
that within which a central sun was to be looked for, that I was
encouraged to map down all the recognized proper motions. To
my surprise I found that in Gemini, Cancer, and Leo, a community
of motion fer more strildng than that noticed by Madler in Taurus
was to be recognized ; and fiirther, that though in other directions,
as I had expected, stellar motions belonging to different depths in
space were intermixed, it was yet possible to trace out laws of
association indicating the existence of drifting star-groups in these
directions also.

I lay very little stress on the indications which have led me to
name the great double cluster in Perseus as more likely to be an
important center of motion than the Pleiades. But it is worthy
of mention that Madler required a star on the Milky Way as the
center of the galaxy, and Alcyone does not lie on the Milky Way;
he required his center to lie ninety degrees from the apex of the
solar motion, and Alcyone does not lie ninety degrees from the
mean of the last deteiminations of that point. The great cluster
in Perseus fulfills both conditions in the most perfect manner.

A careful examination of the proper motions of all the fixed
stars in the catalogues published by Messrs. Main and Stone
(Memoirs of the Royal Astronomical Society, vols, xxviii and
and xxxiii) ha8 led Mr. Proctor to the conclusion that in parts of
the heavens the stars exhibit a well-marked tendency to drift in a
definite direction. " In the catalogues of proper motions, owing
to the way in which the stars are arranged, this tendency is
masked ; but when the proper motions are indicated in maps, by
afiSxing to each star a small arrow whose length and direction
indicate the magnitude and direction of the star's proper motion,
the star-drift (as the phenomenon may be termed) becomes very
evident. It is worthy of notice that Madler, having been led by
certain considerations to examine the neighborhood of the Pleiades
for traces of a community of proper motion, founded on the drift
he actually found in Taurus nis well known theory that Alcyone
(the lucida of the Pleiades) is the common center around which
the sidereal system is moving. But in reality the community of
motion in Taurus is only a single instance, and not the most strik-
ing that might be pointed out, of a characteristic which may be
recognized in many regions of the heavens. In Gemini and Cancer
there is a much more striking drift towards the southeast, the
drift in Taurus being towards the southwest. In the constellation
Leo, there is also a well-marked drift, in this case toward Cancer.

" These particular instances of star-drift are not the less remark-
able, that the stars are drifting almost exactly in the direction due
to the proper motion which has been assigned to the sun, because



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488 Scientific Intelligence,

the recent researches of the Astronomer Royal have abundantly
proved that the apjjsarent proper motions of the stars are not to he
recognized as principally due to the sun's motion. Mr. Stone has
shown even that we must assign to the stars a larger proper mo-
tion, on the average, than that which the sun possesses. Looking,
therefore, on the stars as severally in motion, with velocities ex-
ceeding the sun's on the average, it cannot but be looked upon as
highly significant that in any large region of the heavens there
should be a community of motion such as I have described. We
seem compelled to look upon the the stars which exhibit such com-
munity of motion as forming a distinct system, the m^nbers of
which are associated indeed with the galactic system, but are much
more intimately related to each other. In other parts of the
heavens, however, there are instances of a star-drift opposed to the
direction due to the solar motion. A remarkable instance may be
recognized among the seven bright stars of Ursa Major. Of these,
the stars 1?, /, ^, e, and C are all drifting in the same direction, and
almost exactly at the same rate towards the ' apex of the solar
motion,' that is, the point from which all the motions due to the
sun's translation in space should be directed. If these five stars,
indeed, form a system (and I can see no other reasonable explana-
tion of so singular a community of motion), the mind is lost in
contemplating the immensity of the periods which the revolutions
of the components of the system must occupy. M&dler had
already assigned to the revolution of Alcor around Mizar (C Ursje)
a period of more than 7000 years. But if these stars, which
appear so close to the naked eye, have a period of such length,
what must be the cyclic periods of the stars which cover a range
of several degrees upon the heavens ? In like manner the stars
a, ^, and y Arietis appear to form a single system, though the mo-
tion of a is not absolutely coincident either in magnitude or direc-
tion with that of ^ and y, which are moving on absolutely parallel
lines with eaual velocity. There are many other interesting cases
of the same Kind." The author hopes soon to be able to lay before
the Royal Society a pair of maps in which all the well-re<?ognized
proper motions in both hemispheres are exhibited on the stereo-
graphic projection. In the same maps also the effects due to the
solar motion are exhibited by means of great circles through the
apex of the solar motion, and small circles or parallels having that
apex for a pole. The star-drift described by Mr. Proctor serves to
explain several phenomena which had hitherto been thought very
perplexing. In the first place, it accounts for the small effect
which the correction due to the solar motion has been found to
have in diminishing the sums of the squares of the stellar proper
motions. Again, it explains the fact that many double stars which
have a common proper motion, appear to have no motion of revo-
lution around each other ; for clearly two members of a drifting
system might appear to form a close double, and yet be in reality
far apart and travelling, not around each other, but around the
center of gravity of the much larger system they form part of



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MtBceUaneotM InteUigmce, 4&9

While mftppin^ the proper motions of the stars, Mr. Proctor has
been led to notice that the rich cluster aroond x Persei falls almost
exactly on the intersection of the Milky Way with the great circle
which may be termed the equator of the solar motion ; that is, the
great circle haying the apex of the sun's motion as a pole. This
circumstance points to that remarkable cluster, rather than to the
Pleiades, as the center of the sidereal system, if indeed that sys-
tem has a center cognizable by us. When we remember that for
every fixed star in the Pleiades there are hundreds in the great
cluster in Perseus, the latter will seem the worthier region to be
the center of motion. The author is disposed, however, to
regard the cluster in Perseus as the center of a portion of the
sidereal system, rather than as the common center of the Galaxy.
— Nature^ No. 8, March 3.

V. MISCELLANEOUS 8CIENTIPI0 INTELLIGENCE.

1. NcUional Academy of Sciences: Idat of Papers read at the
Meeting in Aprils 1870, cU Washington, D, U. —

On the measurement of wave-lengths by means of indices of re-
fraction ; by Dr. Wolcott Gibbs.

On the coming Transits of Venus, and the mode of observing
them ; by Prof Simon Newcomb.

Meridional arcs measured in connection with the U. S. Coast
Survey; by Prof J. E. Hilgard.

The Relations of the four Archetypes of structure of the Animal
Kingdom, as parts of one Life System ; by Prof. A. Guyot.

Observations on the Measurement and Iconography of Crania ;
by Dr. Geo. A. Otis, U. S. A.

The northmen in Greenland ; by Dr. I. L Hayes.

Considerations on the apparent inequalities of long period in the
moon's mean motion, and on the possible variability of the sidereal
day ; by Prof Simon Newcomb.

On the deviation of Compasses in iron-clad ships ; by Prof Wm.
Harkness, TI. S. N.

On Artificial deformation of Skulls ; by Dr. Geo. A. Otis, U. S. A.

On the proposed Astronomical observatory in the Argentine Re-
public ; by Dr. B. A. Gould.

Scientific operations now in progress by the Smithsonian Insti-
tution ; by Prof Joseph Henry.

On the comparison of Barometers ; by Dr. B. F. Craig,

On the influence of the interior structure of the earth, on pre-
cession and nutation ; by Gen. J. G. Barnard, U. S. A.

Reduction of photographic observations of Prsesepe ; by Dr. B.
A. Gould.

On the Lignites of Western America ; by Dr. J. S. Newberry.

On the use of certain Artificial lights in photographing objects
as seen with the microscope ; bv Dr. J. J. Woodward, U. S. A.

On the classification of Clouos; by Prof Poey.

New breeds of Hardy Silk Worms, which feed on the " Allan-
thus and Oaks," and the importance of their introduction into the
country as a future industry ; by J. Q. A. Warren.



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440 MisceUaneaus Intelltgence,

On some of the phenomena attending the great tornado thnn-
der-storm of Iowa and Illinois, of June 3rd, 1860; by Wm. L.
Nicholson.

Astronomical Photography ; by Lewis M. Rutherford.

Classification of Mammals ; by Theodore GilL

Redemption periods of life-annuities and reversions ; by E. B.
ElUot.

Description of a new binocular for the Microscope to be used
with high powers ; by F. A. P. Barnard.

Report on Metric Standards ; by J. E. Hilgard.

The Basalts of Oregon, Washington, and Idaho; by R W.
Raymond.

On the polarization of the atmosphere ; by Prof. Poey.

A new form of Quartemions ; by Benjamin Peirce.

2. ITie Mean Pressure of the Barometer and the Prevailing
Winds over the Globe for the Months and for the Tear, Part II ;
bv Alexander Buchan, M. A., F.R.S.E., Secretary of the Scottish
Meteorological Society, &c. 64 pp. 4to ; (from the transactions of
the Rdy. Soc. of Edinburgh, vol xxv.) — ^This memoir presents the
results of a most important research with regard to the lines of
equal barometric pressure, or isobaric lines^ over the globe. The
results as regards the months of January and July are given by
the author on maps in his Handy Book on Meteorology published
two years since. The paper here issued contains the maps for each
of the twelve months, and also another for the means of the year.
We cite a few paragraphs giving some of the conclusions.

Distribution of Atmospheric Pressure^ in December^ January^
anfid February, — ^In these months, the highest pressures are grouped
over the land portions of the northern hemisphere, and the larger
the extent of the land the greater is the pressure. The area of
high barometer (30 inches and upward) embraces nearly all Asia ;
aliEurope, south of the North and Baltic Seas; the North Atlan-
tic, between 16° and 46° lat. ; the West Indies ; North America,
except the north and northwest ; and the North Pacific, between
8° and 24° lat. There are also two regions of high pressure of
comparatively small extent — the one in the South Atlantic, and
the other in the South Pacific.

The regions of low pressure are the northern portions of the
North Atlantic and of tne North Pacific, including portions of the
continents adjoining ; the belt of low pressure in the equatorial
regions, towards which the trade winds dIow ; and the remarkable
depression in the Antarctic regions, which probably is subject to
little variation throughout the year.

In Marchy pressure diminishes over Asia, the middle and south
of Europe, and the United States of America, Everywhere else,
except in the tropics, it is rising. This rise of pressure is most ap-
parent in the temperate regions of the southern hemisphere. In
the north of the Atlantic it is rapidly rising, the average pressure
in Iceland now being 29-609 inches, thus showing an increase of
0*84 inch as compared with January.



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Miscellaneous Intelligence. 441

In Aprily the heavy lines showing a pressure above the average
have now all but left Asia, Europe, and the United States, and the
isobars of 80 inches bowid a belt of high pressure which completely
encircles the globe in the south temperate zone. Pressure con-
tinues to rise in the north of the Atlantic, and to the north of
North America, and it is probable that a space of high pressure (at
least 30 inches) surrounds the North Pole. In this month pressure
is more equally distributed over the globe than in any other month ;
for, excepting the Antarctic Ocean, it scarcely rises anywhere above
30*1 incnes, or ialls below 29*8 inche&

In May, in the north of Europe, in Greenland, and in the north
of America, atmospheric pressure attains the maximum of the
year. Pressure continues to increase over the south temperate
zone, and the isobar of 30*1 inches now nearly extends round the
globe. At this time the highest pressure in the southern hemis-
phere occurs in the southeast of Australia, where, at Deniliquin, it
IS 30*185 inches. Pressure is rapidly falling over Asia and the
United States.

In June, Jvly and August, pressure falls in the central regions
of Asia to about 29*5 inches, u^ this season this great diminution
of pressure, which may be regarded as absolutely determining the
summer climates of Asia, reaches its lowest point. Pressure falls
also in the interior of North America, where at Utah, Great Salt
Lake, it is only about 29*7 inches. The annual maximum of the
south temperate zone is attained in these mouths. The isobar of
30*1 inches goes completely round the globe, and a still higher
pressure prevails over the south of Africa, and over those parts of
the ocean immediately to the west and east of it. In these months
the arrangement of the isobars may be regarded as being, gene-
rally speaking, reversed from that of December, January, and
February, and on this account a comparison of these two groups
of months is very instructive.

From this period, pressures increase over the continents of the
northern hemisphere, and diminish over the south temperate zone,
till the distribution of pressure is regained, which has been already
shown to prevail dunng the winter months. In September and
October, an interesting feature of these lines is a very rapid dimi-
nution of the pressure indicated as taking place in the north of the
Atlantic and adjoining regions. This is the season of the year
when the first great decrease of temperature takes place, which is
accompanied by heavy rains and funous storms. The increase of
pressure in Sweden in October, taken in connection with the
simultaneous decrease in Greenland, Iceland, north of Norway,
and the British Islands, is interesting, as bearing on the trans-
ference of masses of the atmosphere from one region to another.

In November, pressure rises considerably over the continents of
the northern hemisphere, and falls in the south temperate zone;
and the belt of low pressure in the equatorial regions may be re-
garded as now passing completely round the globe. This belt,
towards which the trades on each side of the equator blow, does
not occur in the summer months in the Indian Ocean ; but, on the



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442 MxBoMoLneous IntdUigence.

contrary, there is a continaous diminution of pressure northward,
from Australia and Mauritius to the interior of Asia. It will be
seen that in November, as compared with October, the isobars
have advanced a little northward from the British Isles to Ice-
land, and eastward from Baffin's Bav to Iceland, thus indicating
a^ general increase of pressure over the north of the Atlantic and
regions adjoining. Comcident with this increase of pressure, there
occurs a diminution of pressure to the southeast of it, including
Austria, Italy, and countries adjoining the Mediterranean ; and in
the Atlantic to the south of it, from about latitude 45° to 16**N.
Probably these extensive oscillations of the pressure are parts of
one general movement of the atmosphere, which in one of its mani-
festations has been long known to meteorologists imder the name
of the great Nc^ember wave, but of which no very satisfactory
account has yet been given.

In addition to these changes in the monthly distribution oi the
pressure, it is probable that a system of low pressures traverses the
continent of Africa, following the sun's course; but since the
grounds of this supposition have been recently laid before the So-
ciety, in a paper on " The Determination of Heights, chiefly in the
the Interior of Continents, by Observations of Atmospheric Pres-
sure,"* it is not necessary to reproduce them here. The probable
pressure for the months is shown on the separate charts.

3. Roycd Society of London. — ^Fifty-three candidates have
offered themselves for the fellowship of the Royal Society during
the present session, and in June next fifteen out of the number
will oe elected. — AtlhenoBum^ March 12.

4. Prizes for Comets. — ^The Academy of Sciences at Vienna
have offered eight sold medals for the discovery of as many com-
ets during the coming three years. — Athen.y ibid.

Obituary. — Magnus, of fierlin, the physicist, died in that city,
on the 4th of April.

VL MISCELLANEOUS BIBLIOGRAPHY.

1. Hand Book of the Sulphur- Cure as applicable to the Vine
disease in America, and diseases of ^ppl^ CLua other Fruit Trees ;
by William J. Flagg, author of " Three Seasons in European
Vineyards." 100 pp. 12mo. New York, 1 870. (Harper & Broth-
er). — Mr. Flagg is the proprietor of extensive vineyards in Ohio,
and has devoted much stuay to the management of vines, in health
and in disease. Those who have read his lively " Three Seasons "
need not be told that he handles his theme witn point and vivac-
ity, as well as with a discriminating Judgment Mr. Flagg makes
no claim to a scientific knowledge of microderms, but he elearly
shows, 1st, that mildew in the grape is always due to a fungus
growth, and 2d, that this fungus, wnether Oidium^ JSJrysephe^ or
another genus, is certainly destroyed by the early and thorough
apiilication of flour sulphur. Every cultivator who reads ^e
^ Hand Book,* must at least accept the author's closing words, and
" try it." It is probably a misprint which states the " gramme"

* Prooeedings of the E07. Soa Edin., vol vi, p. 465.



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Miaeellarieoua Bibltography. 448

on p. 50 to be about 28 grains, in place of 15*48 grains. As it
clearly appears that sulphur, in a very fine state of subdivision, is
much pre&red to even finely pulverized roll sulphur, ground in a
mill, would it not be well to try the precipitated sulphur of the
Pharmacopeia (mlphur precipitatum) ^ lac sulphur " or ^ milk of
sulphur,'* which is an impalpable non-crystalline powder, and en-
HieLj icee of the acid which contaminates flour sulphur, and* which
is oJten hurtful to the delicate leaves of the growing grape.
Every farmer could prepare his own product.

2. ITie Chemical ForceSy Beaij Ltght, ElectricUy^ with their appli-
cations to the eocpansicn^ liquefaction^ and vaporization of Solids:
the Steam Engine : Photography: Spectrum analysis: the Oalvanic
battery: Electro-plating: tJie Electrical illumination of Light-
Houses: the Fire Alarm of Cities: the Atlantic Telegraph: an In-
troduction to Chemical Physics, designed for the use of Acade-
mies, Colleges, and Medical Schools. Illustrated with numerous
engravinss, and containing copious lists of experiments, with di-
rections for preparing them. By Thomas Ruggles Pynchon, M. A.,
Scovill Proiessor of Chemistry and the Natural Sciences, Trin-
ity College. 534 pp. 12mo. Hartford, 1870. (O. D. Case <fc Co.)—
Prof Pynchon's book is designed chiefly for a class of readers
who would be unable to follow him with the aid of mathematics.
" All matters of which a knowledge could equally well be obtain-
ed from any good treatise on Natural Philosophy, have been omit-
ted," the author tells us in his Preface : — a statement which appears
hardly sustained by the rather copious list of *' subjects which
have been most carefully elaborated," commencing with 'heat,'
and embracing pretty much the usual range of physical topics.
The work is very neatly printed, and while it is not well adapted
to the accurate drill of the recitation room, it is a good vade me-
ettm for a course of lectures on chemical physics, and for the use
of the general reader, containing a large amount of useful and in-
teresting information on various cognate physical subjects.

8. 7m Life of John Jamss Audubon^ the Naturalist Edited
by his Widow, with an introduction by James Grant Wilson.
443 pp. 12mo. New York, 1870. (G. P. Putnam & Son.)— This
charming biographical sketch of Audubon is an abridgment of a
much more extended memoir prepared by Mrs. Audubon, and sent
in 1867 to a London publishing house, who employed Mr. Robert
Buchanan to prepare a single volume containing about one-fifth of
the original manuscript The American edition contains some
additions, and suppresses several objectionable passages inserted
by the London eoitor. Audubon was a wonderml combination of
artist, naturalist, and enthusiast, fused into an intense individuality
by a strong will, and gilded by heroism and poesy.

American ornithology has always been fortunate in its histori-
ans and devotees, among whom the names Wilson, Nuttall and
Audubon must always stand preeminent; and this loving tribute of
a devoted wife, who was always the sympathizing companion of
her husband, will revive in the present generation something of



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444 Proceedings of Societies^ etc.

the admiration for the genios of Audubon, which his gentle voice
and child-like simplicity ever kindled in his contemporaries.

Audubon kept a copious journal of his daily life, from which
much of the present volume is drawn, and its perusal excites the
hope that in due time we may see the entire work, of which this
sketch may be considered as only the precursor. Inman's spirited
portrait of Audubon, engraved by Hall, prefaces the volume, which
IS in all respects worthy the good taste of the publishers. s.

4. A Physidan^a Problems; by Chablbs Eulh, M.D. pp.
400, 12mo. 1869. Boston, (Fields, Osgood & Co.)— This is a
carefully written and philosophical discussion of some of the
most important 'Problems' which can engage the attention of
the medical man. The list of topics discussed is sufficiently sug-



Online LibraryRodolfo Amedeo LancianiThe American journal of science and arts → online text (page 51 of 109)