DECEMBER 8, 1899. ] 
ties of the Paumotu plateau, at Makatea, 
an elevated island consisting of tertiary 
coralliferous limestone and at the Gambier 
Islands which are voleanic islands of con- 
siderable height. 
A. AGAsstz. 
THE ASTRONOMICAL AND ASTROPHYSICAL 
SOCIETY OF AMERICA. 
II. 
THE REVISED HARVARD PHOTOMETRY. 
In the Harvard Photometry, all stars 
were inserted having the magnitude 6.0 or 
brighter in any of the principal star cata- 
logues then published. Accordingly, as 
was expected, many fainter stars were in- 
cluded, since a star really faint, but esti- 
mated bright by mistake in any of these 
catalogues, would be entered and measured. 
It appears that from this cause, and from 
the varying scale in different catalogues, 
more than six hundred stars are included, 
which are fainter than the magnitude 6.2 
on the photometric scale. (See H. C. An- 
nals, Vol. XIV., p. 479.) Numerous meas- 
ures of the brighter stars have been made in 
recent years, with the large meridian pho- 
tometer which has replaced the instrument 
first used. They include 823 stars meas- 
ured in connection with fainter stars in 
Vol. XXIV., Table I., and 1179 stars in 
Vol. XXIV., Table TV. Measures of all of 
the bright stars south of declination — 30°, 
are published in Vol. XXXIV. ‘ 
The stars of the Harvard Photometry 
were again observed in 1892-1894, and the 
results are now being published in Vol. 
XLIV. A large number of them were also 
measured in 1895-1898, when determining 
the brightness of stars of the magnitude 7.5 
and brighter north of declination — 40°. 
Finally, the stars south of declination — 30° 
are now being remeasured in Arequipa, by 
Professor Bailey. In a recent letter, he 
states that sixteen series were obtained on 
sixteen successive nights, and that 11,448 
SCIENCE. 
841 
settings were made during the month of 
May,1899. It is hoped that this work will 
be completed during the present year. 
It, therefore, appears that seven photo- 
metric catalogues of these stars have been 
prepared. In Vol. XXIV., Table I., some 
stars were observed on only two nights, but 
in all the other catalogues the minimum 
number of nights is three, and for many of 
the stars, especially for those that are 
bright, the number is much greater. When 
the observations were not accordant the 
minimum number of nights was five in 
Vol. XXIV., Part I., and seven or more in 
the other catalogues. The number of pho- 
tometric settings on each star each night 
was generally four, but was occasionally 
eight or more in the later work. The total 
number of photometric settings, including 
those of the fainter stars, will slightly ex- 
ceed one million. It will be seen, there- 
fore, that a large number of measures of all 
the bright stars have been made according 
to the same plan, but with different instru- 
ments and by different observers. Each 
star should appear in at least two of the 
seven catalogues, and generally in three or 
more. 
It is, therefore, proposed to issue a cata- 
logue of all the stars from the north to the 
south pole of the magnitude 6.0 or brighter 
according to the meridian photometer, 
which will show the brightness as given in 
each of the seven catalogues. This work, 
which will be called the ‘ Revised Harvard 
Photometry,’ will also contain other facts, 
such as the approximate right ascension 
and declination for 1900; the designation 
according to Bayer, Flamsteed, the Durch- 
musterung, the Argentine General Catalogue, 
the Harvard Photometry and the Southern 
Harvard Photometry ; the magnitude ac- 
cording to Herschel, the Durchmusterung, 
the Argentine General Catalogue, the Ura- 
nometria Oxoniensis, and the Potsdam Cata- 
logues ; the class of spectrum, and, if pos- 
