it shone with great beauty over the mountains lying in that di-
The usual practice in the sweeping was for Mr. Cogshall to
look through the finder and bring the stars into the field of the
large telescope, while Dr. See examined them with various magni-
fying powers, according to circumstances. It did not take long
practice before Dr. See could tell almost at a glance whether a
star had a companion or not, but in some cases he had to wait for
the image of the star to get quiet, or put on higher power, before he
could make out the existence of a companion with entire clearness
and certainty. Then it was necessary to revolve the micrometer
and measure the position angle and distance at which the com-
panion was seen. While Dr. See was making the measures, Mr.
66 BRIEF BIOGRAPHY AND POPULAR ACCOUNT OF THE
Cogshall sketched the stars in the field of the finder and recorded
the micrometer measures in a book kept at hand for the purpose.
As a rule the dome of the observatory was turned so as to
leave the opening pointed a little to the west of south, and the
stars were therefore observed just after they had passed over the
meridian. This was found to be the most favorable position for
work, and by taking the stars as they went by it saved constantly
moving the dome, which would have consumed much time and
proved to be very troublesome. By working for five or six hours,
Dr. See and Mr. Cogshall used often to examine at least a thou-
sand of the larger stars in the region swept over. This usually
included a belt of the sky about a degree wide, or twice the diam-
eter of the Moon, and extending one-fourth of the way around
the heavens. Such sweeps did not always include every bright
star in the region traversed, for in measuring the stars found to
have companions, some would pass by and have to be left for
At Mexico City the time was so precious that the telescope
was pointed first on the naked eye stars, so conspicuously bright
in that region, and then on those which were invisible to the naked
eye. Among the important stellar systems thus discovered at
Mexico City may be mentioned Eta Centauri, Alpha Phoenicis,
p Velorum, d Centauri, and many others. Some are pairs of
nearly equal stars, lying almost in contact, under the highest
telescopic power; others are composed of a faint companion close
to a bright star; while still others have excessively faint com-
panions far away, and just barely visible to the keenest eye in the
best seeing. About a dozen of these objects looked like planets
shining by reflected light. Their color usually was almost black.
The double stars thus present an amazing variety of phenomena
and some are very highly colored. The tints usually are com-
binations of yellow or reddish light for the larger stars with bluish
or purple companions.
When Dr. See entered upon this survey of the southern double
stars but little work of importance had been done there since the
SWEEPING FOR THE DISCOVERY OF NEW DOUBLE STARS, AT THE CITY OF MEXICO.
In this view Dr. See is at the finder and Mr. Cogshall at the large telescope. Dr. See frequently
changed place with his associate, in order that the latter might have a chance to share in
the work of discovery.
THE DOME OF THE LOWELL OBSERVATORY AT TACUBAYA, MEXICO.
In this view the Dome is turned to the east
UNPARALLELED DISCOVERIES OF T. J. J. SEE 67
memorable survey carried out by Sir John Herschel at the Cape
of Good Hope half a century before (1834-1838) . But it happened
that while Dr. See was working at the Lowell Observatory, Mr.
R. T. A. Innes was working also at the Royal Observatory, Cape
of Good Hope. Sometimes Dr. See would announce his dis-
coveries to Mr. Innes, after they were already independently noted
at the Cape; and, vice versa, Mr. Innes would send notice of dis-
coveries at the Cape which Dr. See already had secured sometime
earlier at Lowell Observatory. It is agreeable to note that this
rivalry always was of the most generous nature, each freely con-
ceding to the other whatever belonged to him.
The survey of Dr. See extended over only two years, the ten-
tative plans for extending it further south, by locating the obser-
vatory in Peru, having to be given up, because of a nervous break-
down unexpectedly experienced by Professor Lowell. This illness
lasted over some two years, and meanwhile Dr. See had become Pro-
fessor of Mathematics in the United States Navy, and was in charge
of the 26-inch telescope of the Naval Observatory at Washington.
Although not completed, owing to Lowell's unexpected ill-
ness, the effect of Dr. See's double-star survey throughout the
world was considerable. It stimulated effort in all southern ob-
servatories, and even helped the double-star work at Lick Observa-
tory, and at many other places in America as well as at Greenwich,
Potsdam, Poulkowa, Paris, Brussels, and other observatories in
Europe. In his introduction to Mr. Innes' "Reference Catalogue
of Southern Double Stars," published by the Royal Observatory,
Cape of Good Hope, in 1899, Sir David Gill, H. M. Astronomer,
speaks of this work of See and Innes as follows:
"Up to the present time no general catalogue of the double
stars of the Southern Hemisphere has been published. The ob-
server who desired to work in this field of research has, therefore,
been compelled either to expend much time in searching for suit-
able objects in the sky, or to consult and compare many different
publications, in order to find the objects most likely to repay labor,
with such means as may be at his disposal.
68 BRIEF BIOGRAPHY AND POPULAR ACCOUNT OF THE
"Greater activity may, in future, be confidently looked for
in double-star work, owing to the increased number of suitable
instruments recently erected in the Southern hemisphere. A
strong additional stimulus will undoubtedly be given by the ex-
ample of Dr. See's labors in this comparatively unexplored field,
and by the publication of his Researches on the Evolution of the
Fourteen years after these words are written we find Sir David
Gill's predictions fully verified. Mr. Innes for some years has
been doing a great deal of double-star work at Johannesburg, in
the Transvaal; and Professor W. J. Hussey of the Detroit Obser-
vatory, University of Michigan, is now in La Plata, extending his
double-star work over the unexplored regions near the South Pole.
It is probable that within five or ten years, several thousand more
new double stars will be discovered in the Southern Hemisphere.
As a sequel to Dr. See's survey at the Lowell Observatory, this is
all very interesting, and very encouraging to those who believe
in scientific progress. Without this work of Dr. See, as Sir David
Gill hints, in the above extract, little or none of this work of ex-
ploration is likely to have been undertaken.
At the City of Mexico very considerable public interest was
awakened by the location of the Lowell Observatory there. Gen-
eral Diaz, the President of Republic, accompanied by Secretary
of State Mariscal, visited the Observatory in state, under a mili-
tary escort, and spent several hours viewing Venus and Mercury
by daylight. All the scientific and literary men in Mexico showed
an equal interest, some coming by day and some by night, to view
the planets, and especially to observe Mars. This was quite
gratifying to Professor Lowell and his associates; and it had the
effect of encouraging Science in Mexico, where the Astronomical
Society of Mexico has since been established, probably as an out-
come of this expedition.
The removal to and from Mexico of all the machinery of the
observatory, and its erection in suitable order was a considerable
mechanical undertaking. Professor Lowell had a good engineer
UNPARALLELED DISCOVERIES OF T. J. J. SEE 69
in Mr. Godfrey Sykes, of Flagstaff, who accompanied the expedi-
tion; but in addition to his help, Dr. See, Mr. Cogshall, Mr. Doug-
lass, and Mr. Drew aided in putting up and taking down the
buildings and machinery. It was found that the Mexican peon
laborers were so wholly devoid of mechanical sense that one Ameri-
can Vas worth a dozen Mexicans in these building and dismounting
Before leaving Mexico, several of the astronomers, including
Dr. See, ascended the volcano Popocatapetl. The trip was very
interesting for the view of the country it offered; and for the sight
of the sulphur refinery, at an altitude of some 12,000 feet, where
the party spent the night.
Professor Lowell was suffering from fatigue and nervousness
before he left Mexico for Boston. After reaching home his ailment
increased, and although he started again for Arizona, and got as
far as Chicago, he had to turn back and take a long rest and treat-
ment before health could be restored. Finally, after two or three
years he was himself again, and could conduct the observatory
with his old time vigor and enthusiasm.
Mr. W. A. Cogshall who assisted Dr. See most of the time in
his work at the Lowell Observatory, developed a good taste for
astronomy, and has since attained considerable prominence as
professor of astronomy and director of the Kirkwood Observatory,
of the University of Indiana. He is an indefatigable worker, and
loves to observe the heavenly bodies. The enthusiasm of one
worker, as is well known, usually bears fruit in another; and of
late years the University of Indiana has produced several prom-
ising young astronomers.
After concluding his two years at the Lowell Observatory,
Dr. See spent part of the summer of 1898 at his old home, in
Missouri, preparing a course of public lectures for the Lowell
Institute. These were on the subject of Sidereal Astronomy, and
were given during the months of December, 1898, and January,
1899. They included the most splendid illustrations known, and
excited generous enthusiasm among the people of Boston. It was
70 BRIEF BIOGRAPHY AND POPULAR ACCOUNT OF THE
generally said that it was the finest and most impressive course
of lectures given at the Lowell Institute since the famous course
delivered by Professor Benjamin Peirce in 1879.
This course of lectures is important in another way. It im-
pressed Dr. See greatly with the hazy veil of cosmical dust spread
over the back ground of the sky in Barnard's magnificient photo-
graphs of the Milky Way, which had excited such enthusiasm in
Boston. In these lectures and another at Wellesley College, Dr.
See pointed out that this dust might be expelled from the stars;
and he thus anticipated Arrhenius and others in publicly advoca-
ting the modern theory of repulsive forces in nature.
Even before Dr. See gave the Lowell lectures, it was known
that Secretary Long and President McKinley were considering
his appointment to a Professorship of Mathematics in the Navy,
with a view of building up the scientific force at the Naval Obser-
vatory in Washington. As soon as his Lowell lectures were finish-
ed, and he was returning to his home by way of Washington, he
found to his astonishment that he had been appointed by the
President and his name already sent to the Senate for confirmation.
While calling on the Secretary of the Navy nobody could have
been more surprised than Dr. See to be told, in reply to his remark
that he hoped to be considered for a vacancy expected to occur
in May: "Professor, I have already made your appointment.
The President approved your selection yesterday and your nomi-
nation has gone to the Senate. You will of course have to pass a
professional and physical examination, but you will have no
difficulty about that." Such a pleasant surprise from Secretary
Long encouraged Professor See very much. For it looked as if a
proper estimate had been put on his strenuous labors of the past
six years, since he had returned from Germany.
Naturally his plans of going on to Missouri had to be sud-
denly altered, and instead he tarried in Washington to pass his
examinations, and be assigned duty at the Naval Observatory;
after which he obtained leave to arrange his business affairs in the
THREE AND A HALF YEARS AT THE NAVAL OBSERVATORY, WASHINGTON .
OBSERVING DOUBLE STARS AND SATELLITES, AND MEASURING THE
DIAMETERS OF THE PLANETS BY DAYLIGHT TO ELIMINATE THE
EFFECTS OF IRRADIATION.
February 7th, 1899, Dr. See was formally nominated* by
President McKinley to be Professor of Mathematics in the
Navy, and the nomination confirmed by the Senate on
February 10. After a short absence at his home in Missouri, Pro-
fessor See was regularly on duty at the Naval Observatory in
Washington. At first he was occupied with the reduction of the
Meridian observations and participating in the observations of
the sun, moon, and planets, with the meridian circle. This is an
important branch of the observatory work, and Professor See
wished to get into close touch with it by actual practice, his pre-
vious experience having been mainly with equatorial telescopes
of large size. But after the retirement of Professor Edgar Frisbie,
U.S.N., in May, 1899, Professor See was given charge of the 12-
inch equatorial telescope of the Naval Observatory, till December,
when he was given charge of the great 26-inch equatorial, with
which he made so many fine observations during the next three
The experience gained in the meridian work during 1899 en-
abled Professor See to effect important improvements in the piers
of the new 6-inch transit circle during the year 1901. This instru-
ment had been mounted on marble piers, but the grain of the
marble was not symmetrical in the two piers, being tilted in one
and horizontal in the other; so that with changes of temperature
*To fill the vacancy caused by the retirement of Professor Newcomb,
March 12, 1897.
72 BRIEF BIOGRAPHY AND POPULAR ACCOUNT OF THE
during the day the azimuth of the instrument varied in a trouble-
some manner. In the summer of 1901 a navy board composed
of Professor See, Professor Updegraff, and Assistant Astronomer
George A. Hill, recommended the removal of the marble piers,
and their replacement by piers of brick, with the result that the
instrument afterwards performed with entire satisfaction, and
gave results of unrivaled accuracy. This improvement of the
six-inch transit circle enable Professor Updegraff to greatly im-
prove the standard of the meridian work of the Naval Observatory.
Professor See's observations with the twelve-inch equatorial
were mainly of asteroids, comets and double stars. Professor
S. J. Brown, U.S.N., was on the point of giving up the large equa-
torial telescope to become Astronomical Director of the Naval
Observatory, and naturally this powerful instrument was assigned
to Professor See as the most experienced astronomer available
for this duty.
Early in the month of October, while the twenty-six-inch was
still officially in charge of Professor Brown, Professor See began
with it a series of observations of the satellite of Neptune. The
seeing at this season of the year often is very fine, because it is
just before winter comes on, and the air quiet, hazy and smoky,
as in Indian summer. These favorable conditions were unusually
conspicuous in 1899, and on October 10, while observing the
satellite of Neptune, Professor See noticed indications of faint
belts on the disc of the planet. They seemed to be bands like
those on Jupiter and Saturn, but very much fainter and more
indistinct, because the disc of Neptune always appears small even
in the largest telescope. The belts on Neptune were observed on
several subsequent occasions, and noted also by Mr. Dinwiddie,
who assisted Professor See in the work on the great equatorial, so
that the existence of the belts is beyond doubt. This beautiful
discovery is a severe test of the astronomer's vision, telescope,
and atmospheric conditions; and it shows that the planet Neptune
is physically of the same type as Uranus, on which belts were dis-
covered by the Henry brothers at Paris in 1884.
VIEW OF THE LARGE TELESCOPE OF THE NAVAL OBSERVATORY AT
Showing the mounting, and the elevating floor, by which the observer is brought to
convenient height in any position of the instrument.
PROFESSOR SEE OBSERVING WITH THE LARGE TELESCOPE OF THE NAVAL OBSERVATORY.
It was with this fine instrument that Dr. See carried out his delicate researches on the diameters of the
Planets and Satellites by daylight and also at night, to eliminate the effects of Irradiation, which
had never been done before.
UNPARALLELED DISCOVERIES OF T. J. J. SEE 73
During the first year after Professor See took charge of the
large equatorial he was occupied mainly with the measurement of
satellites; but later he enlarged the plan of work so as to include
in it the determination of the diameters of all the planets and
satellites. This was, of course, a considerable program, requiring
time, energy and rare mental and physical powers in the observer,
but Professor See was able finally to carry it to a conclusion. The
satellite observations and those on the diameters of the planets
were made simultaneously, without either line of work interfering
with the other. And the work on the diameters of the planets
was done both at night and by daylight, to eliminate the trouble-
some effects of the irradiation.
It is a curious fact of history that as many measurements as
had been made on the diameters of the planets and satellites by
astronomers during the three centuries since the invention of the
telescope by Galileo, no one had previously attempted to eliminate
the irradiation systematically, so as to get the true diameters of
the planets, till Professor See executed this important investiga-
tion in 1901 and 1902. The result was a series of planetary diam-
eters which never can be much improved upon. See's deter-
minations have now come to be recognized as standard, and thus
occupy a classic place in the literature of astronomy.
It should be explained that irradiation makes all the planets
seem to be larger than they really are. It is illustrated by the
apparent enlargement of the outer rim of the new moon and by
the blunting of the points of the crescent, whereas they should
really appear quite sharp. This is owing to the sensation of the
light spreading on the retina of the eye; and this enlargement is
called the irradiation. There was no previous method for getting
rid of this disturbing cause, and Professor See therefore devised
the scheme for taking observations by daylight and afterwards by
night. It was found that the night diameters were considerably
larger than those taken by daylight; and this difference gave the
constant of the irradiation, as found by actual measurement, with-
out regard to any theory. Professor See's empirical method
74 BRIEF BIOGRAPHY AND POPULAR ACCOUNT OF THE
therefore is recognized to be safe, and sound; and this doubtless
is the reason why his results have been so generally accepted by
the scientific world.
When Lord Kelvin was visiting Washington in April, 1902, a
public reception by the leading men of science in the city was
tendered him at the Cosmos Club. At this reception he took par-
ticular pains to inquire of Professor See about the experiments for
finding empirical values of the constants of irradiation for the
different planets and satellites of the solar system. He dwelt on
the problems of irradiation altogether nearly half an hour, and
when satisfied with the account given passed on to the problem
of a resisting medium and the motions of comets, and their de-
rangement in moving through the system of Jupiter's satellites,
which has been considerably studied by astronomers since the
earliest researches of Laplace and Burckhardt a century ago.
The other work carried on so unremittingly by Professor See
from 1899 to 1902 was the measurement of the positions of the
satellites of the solar system. This included extensive observa-
tions of eight satellites of Saturn, four of Uranus, and one of
Neptune; besides measurements of the diameters of all the satel-
lites which have sensible discs. The satellite program was thus
an extensive campaign, and the measures made have since proved
to be accurate and well adapted to the determination of precise
See's observations have been used by Dyson, Bergstrand,
Struve, and several other astronomers for improving the theories
of the motions of these bodies. The two inner satellites of Uranus
proved to be excessively faint; and the same was true of Hyperion
in the system of Saturn, but by screening off the glare of the planet,
Professor See was able to get an excellent series of measures, when
these objects could scarcely be seen by any other astronomer in
the world, owing to the low southern declination of Saturn and
Uranus, which placed them below the reach of European observers.
Altogether it may be said that the campaign on the diameters
of the planets and the positions of the satellites attracted wide and
THE PLANET MERCURY.
As glimpsed by T. J. J. See with the 26-inch refractor at Wash-
ington, in June, 1901. It had long been known from photometric obser-
vations that Mercury behaved like the Moon, flashing out with great
brilliancy near opposition, but otherwise reflecting very little light. If the
surface of the planet were very rough and covered with craters and maria,
as in the case of the Moon, this behavior would be explained. Professor
See was the first observer to glimpse this Moon-like aspect of Mercury
at moments of the best seeing. (From See's Researches, Vol. II.)
A GENERAL VIEW OF THE EARTH AND MOON AS THEY WOULD APPEAR
FROM A POINT IN SPACE.
THE PLANET MARS AS DRAWN AND PHOTOGRAPHED BY LOWELL.
The latter view is the drawing made from a number of the Lowell photographs by the
skillful hand of Mr. W. H. Wesley, Assistant Secretary of the Royal Astronomical Society.
THE PLANETS, THE EARTH AND MOON, AND MARS.
(From See's Researches, Vol. II).
DRAWINGS OF THE PLANET JUPITER.
Made by Keeler at Lick Observatory, 1889. (From See's Researches, Vol. II.)
THE PLANET SATURN,
As Drawn by Proctor, but modified to take account of the Extension of the Dusky Ring observed by
T. J. J. See at Washington in 1901 (A.N., 3768). (From Researches, Vol. II, 1910, Plate XXII).
FIG. o. THE PLANET URANUS, WITH EQUATORIAL BELTS.
As drawn by the Henry Brothers at Paris, 1884.
FIG. b. DRAWING OF THE PLANET NEPTUNE.
Showing the faint equatorial belts discovered by T. J. J. See with
the 26-inch refractor at Washington, Oct. 10, 1899. Views of the
planets Uranus and Neptune. (From See's Researches, Vol. II.)
UNPARALLELED DISCOVERIES OF T. J. J. SEE 75
favorable notice throughout the world. Professor See's great
activity was especially commended by the celebrated French
astronomer Callandreau, and by such observers as Schiaparelli,
Struve, Burnham, Barnard, and a number of others; while the
results of this work naturally were rapidly adopted in the litera-
ture of science.
One other very notable feature of See's labors at the Naval
Observatory relates to the improvement of the personnel. There
was a well known advancement in the standard of the Observatory
as a whole between 1899 and 1902, and in this upward movement
See naturally took a leading part. Young men of promise and
ability were encouraged and given opportunity for some dis-
tinction, with the result that there was a general advance in the
standard and quality of all the scientific work. Accordingly this
proof of progress attracted considerable attention not only in
America, but also in Europe. The work of this period in the
history of the Observatory will always be recognized as one of
high promise and proved efficiency.
See had not only worked very hard ever since entering the
service in 1899, but also without the usual vacations, and in 1901
was found to be suffering from stomach trouble and sleeplessness,
due to disturbance of the digestive processes. He had with diffi-
culty kept up with the heavy program of work in 1901 and 1902;
and when he was detached from the Observatory in September,
1902, a leave of absence for some months of rest was found ad-
visable. Full recovery did not follow very quickly, but was a
gradual process of some years. The difficulty was somewhat
increased by the unfamiliar duties and surroundings at the Naval
Academy. Whilst partial recovery was attained at the Naval
Academy, full recovery was not possible till several years had been
spent at increased outdoor activity in the beautiful climate of