Rodolfo Amedeo Lanciani.

The American journal of science and arts online

. (page 17 of 109)
Online LibraryRodolfo Amedeo LancianiThe American journal of science and arts → online text (page 17 of 109)
Font size
QR-code for this ebook

portant results, was undertaken in 1868, by Dr. W. B. Carpenter
and Dr. Wyville Thomson to explore the region between Scotland
and the Faroe Islands. They were furnished with a Government
vessel, fitted for the purpose, but owing to very bad weather could
use the dredge only nme days during the cruise of six weeks.
They obtained, however, quite a variety of animals at from 400 to
650 fathoms, including the Mhizocrirvus Lofotensis and a remark-
able variety of vitreous sponges, which seem to be very character-
istic of the deep-sea fauna. But their observations upon the tem-
perature at great depths are of the greatest importance. An
extensive area was discovered between the Faroe and Orkney
Islands, where the minimum temperature in 460 to 660 fathoms
was from 32° to 33j°. This region was characterized by an arctic
assemblage of animals and a sandy and stony bottom. South
and west from this " cold area," and extending far to the west of
the Faroe Islands, was a warm area where the minimum tempera-
ture at 450 to 660 fathoms was 46° to 49°, the surface temperature
being 52° to 64^°, while over the " cold area " the surface tempera-
ture was nearly the same, 60° to 62°. The warm area was charac-
terized by a bottom of sofr mud, composed chiefly of the shells of
OlohigerifKE^ ^^ coccolithSj^ ^^ coccospheres^^ and other forms of
Protozoa. Living upon this bottom were various vitreous sponges,
allied to Hyalonema^ and living like it with their long, slender
siliceous spicules buried in the mud like rootlets, and several
Annelids^ jRhizocrinits^ ITophobelemnon, Terebratula^ Lophohelia
proUferaj etc. The character of the bottom and its fauna strik-
ingly recalled the chalk of the Cretaceous period, and the authors
of these discoveries claim that ths chalk formation has been con-
tinuous since the Cretaceous, and is stiU forming in the depths of
the Atlantic. Another expedition was undertaken during the
past season by the same parties, but we have seen no statement of
the results, except that Bucoinum undatum was di'edged living in

No. 11. — List of the Orinoids obUiined on the coasts of Florida and Ctiba, by
the United States Coast Survey OuLf Stream EaDpeditions, in 1867, 1868, 1869.
By L. F. DB PouBTALES. Contains descriptions of eight species of Crinoids (six of
Antedon), with a table showing their distribution.

No. 12. — List of EolothuridcB from the Deep-sea dredgings of the U. S. Coast
Survey, By L. P. db Pouetales. Contains six species, three of which (Echinocu-
cumda typica, CucumanafrondasOf Molpadia borealis) are referred to north European
species, smd two others are regarded as possibly identical.

No. 13. — Report upon Deep-sea Dredgings in the Gu^ Stream^ during &ie Third
Cruise of the U. & Steamer Bibb, addressed to Peofessob Benjamin Pbibce, Su- ■
peiintendent U. S. Coast Survey, by Louis Aoassiz, November, 1869. Contains
a general account of the work done and its results, together with an account of the
rock formations now being deposited in that region, also observations on the young
stages and mode of growtti of several genera of corals, etc

♦ Proceedings of the Royal Society, vol. xvii, p. 168, December, 1868 ; and
Annals and Mag. Natural HiBtory, vol 4, p. 112, August, ^869.

Digitized by VjOOQ IC

132 Scientific Intelh'gevce,

1,800 fethoms,* Dr. E. Perceval Wright also made an exploration
30 miles off Setuval, Portuffal, in search of Hyalonema^ which he
dredged in 450 fathoms, and first ascertained its true mode of life.t
From the same region he and Dr. Gray have described three
species of Halcyonoid corals. By the same expedition a shark
and a small fish were caught at the same depth. The recent
Swedish expedition to Spitzbergen also made important discoveries,
of which we have not yet seen fiill reports.^ Dr. Smitt and Mr.
Ljun^man on the crmse of the Swedish frigate "Josephine,"
which visited the United States last summer, dredged some in-
teresting animals on the newly discovered "Josephine Bank,"
between Lisbon and the Azores, in 11 7 fathoms ; among them are
^MomyceB fnUectosua Lyman, Pteraster militarise Mhizocrimia
lA>fotensis Sars, and Echinocucumia typica Sars, all of which have
been found also off Florida by Pourtales.§

These discoveries have very important bearings upon Geological
science and Physical Geography, as well as Zodlogy, and will
cause important changes m many generally accepted theories.
The following are some of the results already made out :
■^ 1. It is certain that animal life does not begin to diminish sen-
sibly at 100 fathoms and nearly disappear at 300 fathoms, as sup-
posed by Forbes and generally believed previous to these late
mvestieations. It is equally certain that the greatest depths yet
reached with the dredge have an abundant and diversified fauna,
with representatives of most classes of marine animals. The deep-
sea animals are in part new and peculiar to great depths ; in part
found also in shallower waters ; m part previously known as Ter-
tiary or Cretaceous fossils.

2. It follows that abundance of fossils in a geological formation
is not, of itself, evidence of shallow-water origin.

3. It is certain that bright colored anunals are found at the
greatest depths yet explored, and although uniform red and white
are the most common colors among deep-eea animals, yet examples
of nearly all the other colors have been observed, among Protozoa,
Radiata, Mollusca, and Articulates,) as in fact we might have an-

* American Naturalist, voL 3, p. 383, Sept, 1869. Sinoe this artiole has been
put in type I have had the pleasure of reading the preliminary reports of this
most important expedition, by Mr, J. Gwyn Jeffieys, in "Nature," pages 135 and
166, Deo., 1869. The explorations on the Atlantic coast of Ireland by Mr. Jef-
fireys, extended down to ^e depth of 1476 fathoms, revealing a dlversifled fauna of
an arctic character at all depths. Prof W. Thomson conducted the explorations in
the nor^em part of the Bay of Biscay, where the dredgings reached 2435 fath-
oms, with exoeUent results. Dr. Carpenter took charge of the additional explora-
tions north of Scotland. The results of this expedition are of great interest and
Ibe new discoveries very numerous. It added 117 species of moUusca to the 451
previously regarded as belonging to the British fauna Of these 56 are new to
science. The mollusca obtained in 2436 fathoms are Pectm feneatraiiM (Mediter-
ranean), Dacrydkim vUreum (Arctic), Sorobieularia niiida (Finmaik to Sidiy), Nbo-
ra (new), DerUoHum (new).

•f Annals and Magazine. of Nat Hist, Oct, 1868.

^ The Swedish expedition of 1868 obtained in soundings a Owma and a frag-
ment of Astorte fh)m 2600 fathoms.

f Bulletin Mu& Comp. Zo6l, pp. 347 and 357.
See the remarks of "E^t Sara on this su^eot in the work quoted above.

Digitized by


Botany and Zoology. 138

ticipated from the fact that many burrowing annelids, ornstacea,
and shells, which are rarely if ever exposed to the light, are bril-
liantly colored.

Therefore the presence of color-markings on fossil shells is not
an evidence of their shallow-water origin, as believed by Forbes
and others. The finely colored specimens of VohUa Junonia^
dredged living by Pourtales in 360 fathoms, are a sufficient refu-
tation of this theory.

4. Prof. Sars mentions several species of deep-sea Crustacea hav-
ing perfectly developed eyes, showing that light penetrates to far
greater depths than is commonly supposed.* But the decrease
of sea-weeds and their almost complete disappearance at about 100
fathoms may perhaps be due to the diminution or modification of
the light

5. ITie generally received theory that the temperature of the
water at great depths is everywhere the same, in all latitudes, viz :
that at which sea-water has its greatest density, formerly said by
Herschel and others to be 39°, but more recently shown to be that
of the freezing point of sea-water (26°*4 to 27°'4 Fahr.), is not true,
at least for depths down to 700 fathoms, as shown by the observa-
tions of Thomson and Carpenter.

6. The same observers have satisfactorily shown that temperature
is the main agent in determining the distribution of deep-sea ani-
mals, which had been previously shown to be the case among
shallow-water forms, and that mere depth or pressure has little or
no infiuence directly. But the chemical composition of the water
fas the amount of oxygen) a ad the character of the bottom doubt-
less have their influence.

7. The last observation is connected with the discovery of two
contiguous, but distinct, deep-sea faunae, living side by side at
similar depths (400 to 600 fathoms) ; one eminently arctic in
character, occuj)ying the "cold area" on a sandy and stony bottom ;
the other simihar to that of the region between Florida and Cuba,
and occupying the " warm area," with a bottom of calcareous in-
fusorial mud. The last fauna, or at least some of its species, ex-
tends over a region of vast extent, both in latitude and longitude,
some of the species ranging from Florida to within the Arctic
Circle, and on both sides of the Atlantic.

8. The discovery of species, genera, families, and even sub-orders,
supposed to have become extinct, leads us to expect that other lost
forms may still have living representatives in the vast unexplored
regions of the ocean. f Among the remarkable discoveries, may
be mentioned the Rhizocrinus ; the HaplophyUia paradoxa Pourt.,
a living representative of the " Rugosa " group of corals, supposed

* Other remaricable instances are mentioned by Jeffreys: as Lacuna tenella and
a stalk-eyed crab from 808 fathoms; Trochus minuHssimus Mighels and Ampelisca
from 1230 fathoms; a stalk-eyed crustacean from 1476 fathoms; a large new Fu-
mu from 1207 fathoms; a Fleurotoma from 2090 fathoms; and Octopus cocco from
632 fathoms, all of which are said to have well developed eyes.

f The Porcupine expedition obtained a number of species of shells previously
known only from the Tertiary (Coralline Crag and Red Crag).


Digitized by VjOOQ IC

134 Scientific Intelligence,

not to have lived since the Carboniferous period; various new
forms of sea-urchins, described by A. Agassiz, having their nearest
allies in the Cretaceous, etc. The discovery of the living Cys-
tidean noticed in the last number of this Journal is another fact
of the same kind, and so remarkable that it mav not seem unrea-
sonable to anticipate hereafter the discovery of living Ammonites
and Trilobites.

9. These investigations have thrown great light upon the mode
of deposition of certain geological formations, especially the chalk,
and at the same time illustrate the manner in which, under the in-
fluence of currents of different temperatures, a chalk and a sand-
stone, with entirely distinct faunae, may be deposited side by side
at the same depth and, supposing the currents to be modified, how
the two might alternate, thus accounting for the extinction of faunae
and the re-appearance of " colonies," as noticed by Barrande.

1 0. Dr. Carpenter and Thomson claim that the chalk formation
now depositing in the deep Atlantic is a direct continuation of the
chalk formation of the Cretaceous period, some of the living spe-
cies being regarded as identical with Cretaceous fossils, while
others, closely allied to fossil forms, are supposed to have been mod-
ified during the lapse of time by " natural selection," or in some
other way.

3. CcUalogue of the Mammals of Massachicsetts ; with a Criti-
cal Revision of the Species; by J. A. Allen. Bulletin of the Mu-
seum of Comp. Zoology, No. 8. Cambridge, October, 1869. — This
includes not only a list of the species, with their principal syiionyms,
but also valuable information concerning their distribution, and
their relations with the species of the old world. Mr. Allen admits
much greater variations in the species of mammals than most mod-
em writers, and shows that this variation is often as great in speci-
mens from different parts of North America as between specimens
from the two continents. Consequently he has regarded many of
our mammals as identical with those of Europe and Asia. Among
these are the black bear, common wolf, red fox, two weasels, mink,
sable, beaver, moose, and reindeer. In some cases, however, he
has probably gone altogether too far in uniting species ; as in con-
sidering the black-bear, the grizzly-bear, the barren ground bear,
and the European bear all one species ; and in his treatment of
the genus Blarina. He has also overlooked a specimen of Near
sorex palustris vn t\iQ 'Mw^evcm^ from Norway, Me., described by
me in the Proc. Boston Society of Natural History. v.


1. Report on the Recent Eclipse of the Sun ; issued under the
direction of the Superintendent of the Naval Observatory. —
This handsome volimie of more than 200 pages has appeared
first of any of the reports of the government expeditions, only
detached portions of those of the Nautical Almanac and Coast
Survey having yet been published. Commodore B. F. Sands,

Digitized by VjOOQ IC

Astronomy, 136

Supt of the Naval Observatory, took early measures to secure
thorough observations, and assigned four of the five professors
and two of the other astronomers at that institution, to the duty
of observing the eclipse. In pursuance of the plans Prof. Hall
and Mr. Rogers repaired- to rlover Bay, on the Asian shore of
Behring's 8traits,Profes6ors Xewcomb, Harkness and Eastman estab-
lished themselves at Des M^oines in Iowa, and Mr. Bard well went
to Bristol, Penn. The War Department lent, its assistance by
detailing Dr. Curtis of the Army Medical Museum, who has won
deserved distinction by his success in micio-photography, and who
accompanied the Des Moines party. The volume contains reports
from each of these gentlemen, and to these are added others from
Mr. J. H. Lane, of Washington, from 3Ir. W. S. Gilman, Jr., of
N. Y., a lover of astronomy who has given special attention to
solar observations, and from Gen. A. J. ilyer, chief signal officer
of the array, who witnessed the eclipse from the summit of a moun-
tain in Southwestern Virginia,-— these with the prefatory intro-
duction of Commodore Sands composing the work now issued,
which is copiously illustrated with cuts and engravings.

Prof Newcomb's point of observation was near the Court-house
in Des Moines, latitude 41° 35' 4', on long. P' 0'" 17'*0 west from
Washington. Following out the ideas previously sucjgested by
him in this Journal, he affixed circular screens of different di-
ameters to a horizontal aim, projecting from the gable end of the
Court-house, so as to occult the sun for his points of observation ; the
largest being intended to hide the corona from the field of his 4-iiich
comet-seeker. Ailer a sharp determination of the first contact with
a power of 40, in this instrument, and an aperture reduced to one
inch, he carefully pointed an 8-inch telescope, roughly mounted for
the occasion, and the comet-seeker, to the sun at known moments;
thus fixing their positions for the purpose of mapping the places
of any objects which the totality might disclose in either field of
view, after which he designed moving the telescopes into other
positions, and counting any objects which might there be visible.
Then retiring into a dark place, he awaited the total phase.

The corona appeared less bright than he had anticipated, and
careful scrutiny along the ecliptic showed not the faintest trace of
any flush of light extending beyond the rest in that direction.
Nothing was visible in either of the two telescopes, nor did a
sweep near the ecliptic with the comet-seeker disclose any object
whatsoever. This important question being thus answered, and
the visibility of any inferior planet or group capable of accounting
for the motion of the perihelion of Mercury being made highly
improbable, Prof Newcomb proceeded to the study of the corona,
with and without the aid of the comet-seeker. The great protu-
berance in the S.W. quadrant seemed to him strongly pink, not
uniform in structure, nor at all resembling a flame, but like a huge
pile of cumulus clouds, illuminated by white and red light. He
was able to trace the corona with his naked eye only to a distance
equal to the moon's semidiameter and he saw no long rays of light,

Digitized by VjOOQ IC

186 Scientific Intelligence,

but a jagged and serrated edge. The sky at Des Moines was how-
ever quite hazy. But seen through a green glass the corona
seemed composed of four or five prominent portions, smooth in
outline, shading away imperceptibly, and in no case exceeding ^'
in height He regards the serrated appearance and the pointed
rays as subjective phenomena. The moment of end of totality
was noted with the naked eye, and the last contact with the
comet-seeker, as before. Comparing his observations with the
computed times, he finds the contacts to have occurred later than
predicted by 12''*5 for the first, 10"-4 for the third, and 7*'8 for the
last ; whence he infers

Peirce's J) — Hansen's is too great by 5"*3,
whereas, Hansen's J) — LeVerrier's is too great by 2 7.

Prof. Harkness constructed a building for himself. Prof. Eastman
and Dr. Curtis at another point in tne city of Des Moines, and
determined his position as latitude 41 ** 36' 35^'*9, long. 1^ 6" 16» -06
"W. from Washmgton, by means of observations which are repro-
duced with great fiillness of detail At the beginning and end
of the eclipse he was engaged with Dr. Curtis in taking photo-
graphs, upon which he had decided to rely for the times of first
and last contact ; but during the totality he devoted himself en-
tirely to the spectroscope. W ith this he obtained, from a very bright
part of the corona in the long beam to the southward, a continuous
spectrum without absorption lines, but with a single bright line at
1497 of KirchhoflTs scale. From the great protuberance at 240**
he obtained the lines C and F, that near D, and three others, two
of which were b and the well-known third hydrogen line. The
remaining one was that which he saw in the corona, and in all the
protuberances without exception, and recorded as corresponding
to K. 1497. It must we think have been K. 1474, which was
recognized by so many other observers and which Lockyer and
Young have always found in the chromosphere. The moderate
dispersive power of Prof. Harkness's spectroscope would, as he
states, render it diflicult for him to discriminate with it between
near lines.

Prof. Eastman's report contains the results of meteorological
and photometric observations (which during the two days preced-
ing tne eclipse must have been far from encouraging), of observa-
tions of the contacts and of the corona. Of this and the appear-
ances of the protuberances to him, he has given two colored
engravings. In each the same outline serves for the corona ; and
indeed he expressly states that he ** could not detect the least
change in the color or position of the rays during totality."
Beside these labors he assisted Prof Harkness during the totality,
by directing the spectroscope. Amid so many avocations it is sur-
prising that Prof Eastman could have accomplished so much, and
that so well We cannot avoid the conviction that had he been
master of his own time during the total phase, he would not have
failed to detect the decided fluctuations of form which the corona
exhibited to more than one observer at Burlington. Like Pro£
Newcomb, he found the color of the protuberances strongly red»

Digitized by VjOOQ IC

Astronomy. 137

Dr. Curtds's report relates to the photographic operations which
are described with very great minuteness. To those familiar with
the exquisite photographs which he has made at the Army Med.
Moseom, it is needless to say that his preparations were evidently
made with great forethought, and that abundant skill was dis-
played. A naze which veiled the sky, rendered a much larger
exposure requisite than would otherwise have been given, but the
photographs are of hjgh excellence. The two taken during totality
are given in engraved representations, impressions from the origi-
nals accompanying. These are very fine, rivaling those of the
Burlington and Ottumwa parties. For the first, the exposure was
66 seconds ; but details of the protuberances are beautifully shown,
which would not have borne an exposure of one-third that length in
a transparent atmosphere. Even the lunar motion seems scarcely
to have interfered with the definiteness of the image.

It is to be regretted that a national enterprise carried out at the
public expense should ever be made an agency for personal pole-
mics, which indeed seem peculiarly out of place when ajmed at
any private citizen of the same nation, since he is theoretically
one of those in whose behalf the investigation has been made.
The greater part of one of the quarto pages is occupied by a note
in fine print m which Dr. Gould is rather sharply assailed for his
views as given on p. 485 of our last number. This is no place for
any maintenance of those views, but two paragraphs deserve a word
of comment

*' Dr. Gould adduces, as an additional argument in favor of his assumption, the
observation that the long coronal beams appeared to him to be " variable," while
the *' aureole " photographed was evidently " constant " during the time of totality.
This argument however loses some of its force when it is remembered that to
other observers the corona appeared to the eye absolutely unchangeable both in
form and position during the whole period of the total obscuration."

We are far from attributing to Dr. Curtis any intention of giv-
ing his language the discourteous significance which some might
inter, otherwise no rejoinder could be possible. But we would
suggest that special observations devoted to a particular point
should prima facie outweigh general negative impressions. In
the present case, if Dr. Gould's evidence be regarded as for any
reason incompetent, there happens to be corroboration of his state-
ment by other gentlemen whose attention he called to this point.
And there is in addition the reasonable certainty that less than a
twelvemonth will decide the question definitely, since attention
will doubtless be specially directed to this point at the eclipse of
Dec next. Perhaps it might be the wisest, as it would certainly
be the most considerate, course, to await such decision.

In the other passage Dr. Curtis says : —

*• the circumstance affords but another example of the necessity that

a critic before attempting to draw scientific inferences from photographic repre-
sentations should himself become something of a photographer And by a

singular coincidence, evidence that Dr. Qould has not a practical acquaintance with
the art would seem to be afforded in this same published letter by his total mis-
interpretation of another purely photographic effect, viz : the apparent encroach-

Digitized by VjOOQ IC

138 Scientific InteUigence,

ment of the prominences upon the disk of the moon as seen in the photographfl.
This curious appearance, instead of being due to *' specular reflection " is wholly a
dark-room phenomenon, aa will be explained in the text."

That Dr. Curtis's explanation is entirely adequate in most cases
we readily concede. ^But when Ulloa in IV 78 saw the brightness
of the protuberances projected so far upon the lunar disk that he
thought the sun was shining through a hole in the moon, there
were no photographs. And had circumstances brought to Dr.
Curtis's notice as many dozens of cases as have come to our knowl-
edge, in which the great protuberance of last August was seen
both by scientists and laymen, with and without optical aid, to ap-
pear as " a deep notch in the moon," we think he would have qual-
ified his language. Dr. Gould has expressed his belief that this
phenomenon is due to specular reflection from the lunar surface ;
others may with great reason attribute it to the influence of irradi-
ation ; but it cannot be solely a photographic effect^ however such
effects may coincide.

Dr. Curtis has also given the results of some interesting experi-
ments made to determme the origin of the glow seen upon the sun,
around the moon's limb, on the photographs ; a glow which has
been found real and not the result of contrast, in all the impres-
sions taken last August. This he believes to be a result of dim-ac-
tion, a view which we fully shared, as those present at the August
session of the National Academy will remember. And by experi-

Online LibraryRodolfo Amedeo LancianiThe American journal of science and arts → online text (page 17 of 109)