John Macon Thome was born at Palmyra, Pennsylvania, U.S.A.,
on August 22, 1843. He received a college education, and in 1870
took the degree of D.Sc. at the Lehigh University. In 1870 Dr.
B. A. Gould was appointed by the Argentine Government to
establish a national astronomical observatory at Cordoba, where he
arrived in September of that year. The selection of Cordoba as an
•especially desirable place was chiefly due to Lieutenant Gilliss,
whose astronomical mission to Santiago de Chile, 1850-1852,
Enabled him to form a sound judgment as to the relative
advantages of different points in South America for astronomical
purposes. Before leaving the United States, Dr. Gould had engaged
four assistants, of whom Dr. Thome was the senior, and they arrived
at Cordoba at the end of September 1870. At this time Dr. Thome
possessed no special astronomical training or experience. His
subsequent career and the excellent work that has been accomplished
at the Cordoba Observatory show the wisdom of Dr. Gould’s
selection. Speaking in after years of his assistants, Dr. Gould said
he had been singularly favoured. “ Their unselfish devotion to the
great undertakings in which they took part, their loyalty, trust-
worthiness, and ability, have been beyond all praise.”
in Dr. Gould’s absence in 1874 and 1876 the observatory was
left in charge of Dr. Thome, and on Gould’s resignation in 1885
Thome was appointed Director.
Thome’s directorship of the Cordoba Observatory began under
most depressing and disadvantageous circumstances. He was
practically alone, for Mr. Tucker, his one assistant, had only just
joined him, and the condition of things was aggravated by the
disastrous financial crisis which shortly ensued in Argentina, which
rendered all his efforts to increase the staff, by engaging men
abroad upon a paper basis, without result. In his own words,
institution upon the smaller salaries consequent upon a vanishing
budget, which cut off from me all hope of obtaining trustworthy
help abroad, has been attended with painful experiences, and I
have repeatedly been compelled to stop and train new men, and to
repeat operations performed by inefficient and negligent or designing
assistants.”
But Thome’s zeal and devotion were quite undeterred by such
adverse conditions, and he determined to undertake the great task
of continuing the Durchmusterung of Argelander and Schönfeld
to embrace nearly the whole of the southern heavens. For this
work he employed a portable equatorial with an object-glass by
Alvan Clark of I2’5 cm. aperture and 168 cm. focal length, and
the plan of operation was similar to that adopted at Bonn, except
that transits were recorded chronographically instead of by the
particular eye and ear method of Argelander.
The Cordoba Durchmusterung has been completed for the
region from 220 to 65o south declination. The results are contained
in four volumes (of which three have at present been distributed),
and give the positions and brightness down to the 10*5 magnitude
of 630,000 stars, resulting from over 1,800,000 observations.
Eighteen charts, containing 550,000 stars, have also been prepared.
The larger part of the observations for this great and valuable work
were made by Thome. Indeed, for the four years 1894-1897
he made every observation himself, with the assistance of Mrs.
Thome and Mr. Schuldt as recorders. It is impossible not to'
speak in the highest terms of the ability and untiring devotion of
Thome in prosecuting and accomplishing this important and
valuable contribution to astronomy. He will always occupy an
honourable place in the roll of great workers in that science.
In the year 1900 the Paris Astrographic Congress resolved to
ask the Cordoba Observatory to take over the photographic zone
between the 23rd. and 31st. degrees of south declination, which had
been previously assigned to the observatory at La Plata. This was
accepted by Thome, and by the beginning of 1902 his observatory
was equipped with an astrographic telescope by Gautier and all
necessary apparatus ; since then the work has been prosecuted
with the Director’s characteristic energy.
Though no paper by Thome appears in the publications of this
Society, he contributed various papers to astronomical journals on-
comets, variable stars, minor planets, etc.
He died at Cordoba rather suddenly on September 27, 1908.
He was elected a Foreign Associate November 10, 1899.
E. B. K.

John Macon Thome was born at Palmyra, Pennsylvania, U.S.A.,
on August 22, 1843. He received a college education, and in 1870
took the degree of D.Sc. at the Lehigh University. In 1870 Dr.
B. A. Gould was appointed by the Argentine Government to
establish a national astronomical observatory at Cordoba, where he
arrived in September of that year. The selection of Cordoba as an
•especially desirable place was chiefly due to Lieutenant Gilliss,
whose astronomical mission to Santiago de Chile, 1850-1852,
Enabled him to form a sound judgment as to the relative
advantages of different points in South America for astronomical
purposes. Before leaving the United States, Dr. Gould had engaged
four assistants, of whom Dr. Thome was the senior, and they arrived
at Cordoba at the end of September 1870. At this time Dr. Thome
possessed no special astronomical training or experience. His
subsequent career and the excellent work that has been accomplished
at the Cordoba Observatory show the wisdom of Dr. Gould’s
selection. Speaking in after years of his assistants, Dr. Gould said
he had been singularly favoured. “ Their unselfish devotion to the
great undertakings in which they took part, their loyalty, trust-
worthiness, and ability, have been beyond all praise.”
in Dr. Gould’s absence in 1874 and 1876 the observatory was
left in charge of Dr. Thome, and on Gould’s resignation in 1885
Thome was appointed Director.
Thome’s directorship of the Cordoba Observatory began under
most depressing and disadvantageous circumstances. He was
practically alone, for Mr. Tucker, his one assistant, had only just
joined him, and the condition of things was aggravated by the
disastrous financial crisis which shortly ensued in Argentina, which
rendered all his efforts to increase the staff, by engaging men
abroad upon a paper basis, without result. In his own words,
institution upon the smaller salaries consequent upon a vanishing
budget, which cut off from me all hope of obtaining trustworthy
help abroad, has been attended with painful experiences, and I
have repeatedly been compelled to stop and train new men, and to
repeat operations performed by inefficient and negligent or designing
assistants.”
But Thome’s zeal and devotion were quite undeterred by such
adverse conditions, and he determined to undertake the great task
of continuing the Durchmusterung of Argelander and Schönfeld
to embrace nearly the whole of the southern heavens. For this
work he employed a portable equatorial with an object-glass by
Alvan Clark of I2’5 cm. aperture and 168 cm. focal length, and
the plan of operation was similar to that adopted at Bonn, except
that transits were recorded chronographically instead of by the
particular eye and ear method of Argelander.
The Cordoba Durchmusterung has been completed for the
region from 220 to 65o south declination. The results are contained
in four volumes (of which three have at present been distributed),
and give the positions and brightness down to the 10*5 magnitude
of 630,000 stars, resulting from over 1,800,000 observations.
Eighteen charts, containing 550,000 stars, have also been prepared.
The larger part of the observations for this great and valuable work
were made by Thome. Indeed, for the four years 1894-1897
he made every observation himself, with the assistance of Mrs.
Thome and Mr. Schuldt as recorders. It is impossible not to'
speak in the highest terms of the ability and untiring devotion of
Thome in prosecuting and accomplishing this important and
valuable contribution to astronomy. He will always occupy an
honourable place in the roll of great workers in that science.
In the year 1900 the Paris Astrographic Congress resolved to
ask the Cordoba Observatory to take over the photographic zone
between the 23rd. and 31st. degrees of south declination, which had
been previously assigned to the observatory at La Plata. This was
accepted by Thome, and by the beginning of 1902 his observatory
was equipped with an astrographic telescope by Gautier and all
necessary apparatus ; since then the work has been prosecuted
with the Director’s characteristic energy.
Though no paper by Thome appears in the publications of this
Society, he contributed various papers to astronomical journals on-
comets, variable stars, minor planets, etc.
He died at Cordoba rather suddenly on September 27, 1908.
He was elected a Foreign Associate November 10, 1899.
E. B. K.