Marcu 8, 1901.] 
also completed * and the report will soon be 
ready for the printer. The relations be- 
tween the measures of the earth made in 
the United States and the previously ac- 
cepted values for the earth’s size are shown 
in the table given below. 
The last two determinations shown in 
the table are of light weight in comparison 
with the preceding three. 
A study of these values will show that 
the modern observations in the United 
States indicate that the true value of the 
equatorial radius lies between the Clarke 
and Bessel values, but nearer the Clarke 
value, and for the polar semi-axisis a little 
greater than the Clarke value. 
SCIENCE. 
383 
axis so computed will differ from the Clarke 
values of 1866 by as much as 500 meters, 
and it is about an even chance that either 
value will not differ from the corresponding 
Clarke value by more than 170 meters, this 
being about the height of the Washington 
monument. In other words, there is little 
likelihood that the Clarke spheroid of 1866 
now used as the standard in this country 
differs from the spheroid which will most 
nearly fit this country alone by more than 
one part in 12,000, and there is an even 
chance that it does not differ from it by 
more than one part in 36,000, 
It is reasonably safe to make the same 
prediction in regard to the earth spheroid, 
Equatorial | Polar semi- | Compression 
Tadius, a, in _ axis dD, (a-b)/a. 
meters. in meters. 
Besselispheroidyoied Sale erveitelelelettetleleleleralelaleleleleletelel=la}ahelateleloiereretare 6,377,397 6,356,079 1/299.2 
Clarke spheroid of 1866 .........0 ces scee sees eccceescseseeees 6,378,206 6,356,584 1/295.0 
Harkness, 1891. From ‘The Solar Parallax and Related Con- 
stants,’ Washington, 1891, p. 138. From a variety of sources...| 6,377,972 6,356,727 1/300.2 
The spheroid determined by the 39th parallel triangulation and 
the Lake Survey are of the meridian.....-....... ........-- 6,377,912 6,356,309 1/295.2 
The spheroid determined by the 39th parallel triangulation and 
IDSA) Ag ogadauepacuscooousndadsunocdHBoanGapooLeDodos 6,378,027 6,356,819 1/300.7 
astern oblique are of the United States ....................- 6,378,157 6,357,210 1/304.5 
Nantucket and Pamlico-Chesapeake arcs of meridian and Peruvian 
ERG OF WAAACIEM. 0009005 0000c000200 ODA vaNZOONDDNSG0ND000000000 6,378,054 6,357,175 1/305.5 
Lake Erie are of parallel and Peruvian arc of meridian .......... 6,379, 822 6,357, 716 1/288.6 
Having in mind the large number of as- 
tronomical stations attached to, and the 
large area covered by, the ares already util- 
ized in the United States, as indicated 
above, it is reasonably safe to predict that 
if the United States is eventually com- 
pletely covered by triangulation and as- 
tronomical stations are liberally supplied 
everywhere, and the mean figure deduced 
from these observations alone, regardless 
of those made in other countries, neither 
the equatorial radius nor the polar semi- 
* See ‘ Recent Contributions to our Knowledge of 
the Earth’s Shape and Size by the United States 
Coast and Geodetic Survey.’ C. A. Schott, The Na- 
tional Geographic Magazine, January, 1901, pp. 39- 
41. 
or the spheroid which will most nearly fit 
all the measures which may hereafter be 
made in all countries, as has been made 
above for the spheroid which will most 
nearly fit the United States. 
Joun FirumMorE HAyrorp. 
U.S. CoAST AND GEODETIC SURVEY. 
THE SAN JOSE SCALE IN JAPAN. 
THe insidious invasion of the eastern 
United States by the San Jose scale (As- 
pidiotus perniciosus)—the name gives unde- 
served notoriety to the California city—has 
come to be so formidable that the pest is 
now recognized as one of the most seri- 
ously threatening dangers to American 
