UNITED STATES COAST AND GEODETIC SURVEY. 
417 
Ivory (James)—Continued. 
On the methods proper to he used for deducing 
a general formula for the length of the seconds pen 
dulum, from a number of experiments made at differ 
ent latitudes. 
Phil. Mag. (Tilloch), lxviii, 1826, 241-245. 
Disquisitions concerning the length of the sec 
onds pendulum, and the ellipticity of the earth. 
Phil. Mag. (Taylor), lxviii, 1826,246-251. 
Investigating a general formula for tlie length of the 
seconds pendulum in all latitudes and comparing it 
with all the tolerably exact experiments that have 
presented themselves. 
On the grounds for adopting the ellipticity of the 
earth deduced by Captain Sabine from his experi 
ments -with the pendulum in his work lately pub 
lished. 
Phil. Mag. (Tilloch), lxviii, 1826, 321-326. 
Short abstract of M. de Freycinet’s experiments 
for determining the length of the pendulum. 
Phil. Mag. (Tilloch), lxviii, 1826, 350-353. 
: Anonymous. Ivory’s mode of finding the length 
of the geodetic curve. 
Quart. Journ. Sei., xxi, 1826, 361-363. 
: Bessel (F. W.). Betreffend beide Methoden 
geodätischer Berechnung. 
Astron. Nadir., v, 1827, 177-180. 
Notice relating to the seconds pendulum at Port 
Bowen. 
Phil. Mag. (Taylor), i, 1827,170-171. 
On the ellipticity of the earth as deduced from 
experiments with the pendulum. 
Phil. Mag. (Taylor), in, 1828, 165-173. 
It is remarkable that the pendulum experiments within 
30° of the equator are very irregular. This may he 
that gravity is unequally distributed in that quarter 
of the globe, or the observations were erroneous. 
Additional discussion respecting the ellipticity 
of the earth as determined by experiments made with 
the pendulum. 
Phil. Mag. (Taylor), in, 1828,206-210. 
In deducing the figure of the earth from the observed 
length of the pendulum, I have always thought it 
necessary to leave out a few of the experiments that 
were inconsistent with the rest. The inconsistency 
is proved by comparing tho pendulum on the same 
parallel, or nearly on the same, when a correction 
must be applied. If they are excessively irregular, 
I always rejected such as were irreconcilable with 
the rest. 
A letter to the editors, relating to the ellipticity 
of the earth as deduced from experiment's with the 
pendulum. 
Phil. Mag. (Taylor), in, 1828,241-243. 
It is also stated that it is useless to involve terms of the 
second order. 
— On the figure of the earth, as deduced from meas 
urements of different portions of the meridian. 
Phil. Mag. (Taylor), in, 1828, 343-349, 431-436. 
From the Pern, India, France, and England arcs an el 
lipticity of was found. 
On the latitudes and differences of longitude of 
Beachy Head and Dunnose, in the Isle of Wight, as j 
laid down in the trigonometrical survey of England; ! 
H. Ex. 17 27 
Ivory (James)—Continued. 
aud the length of a degree perpendicular to the me 
ridian at the latitude of Beachy Head. 
Phil. Mag. (Taylor), iv, 1828, 6-11. 
Criticises the formula used by the trigonometric survey 
for finding difference of longitude. Segments of the 
above arc showed a decrease in the length of a de 
gree in going north. Ivory found an error of 18" in 
the amplitude, which, when applied, gave increasing 
degrees towards the north. 
On measurements on the earth’s surface perpen 
dicular to the meridian. 
Phil. Mag. (Taylor), iv, 1828,189-194. 
States that the measurements in England and India be 
long to the same spheroid, but disagree with the 
French, while ameasmed arc perpendicular to the 
meridian in France agrees with the trigonometric 
degree, which tends to throw doubt npon the English 
methods of computing difference of longitude. 
On the method employed in the trigonometrical 
survey for finding the length of a degree perpendic 
ular to the meridian. 
Phil. Mag. (Taylor), iv, 1828, 241-245. 
Stating that the azimuth between two points on a sphe 
roid is not the same as on a sphere when the lati 
tude and difference of longitude are the same ; hence 
the error in the formula used by the trigonometric 
survey for computing difference of longitude. 
On the method in the trigonometrical survey for 
finding the difference of longitude of two stations 
very little different in latitude. 
Phil. Mag. (Taylor), iv, 1828,432-435. 
Referring to the methods of the trigonometrical survey, 
says: “It is just to characterize the method of calcu 
lation in the survey as the greatest delusion that has 
ever prevailed in practical mathematics.” 
On the method of deducing the difference of lon 
gitude from the latitudes and azimuths of two sta 
tions on the earth’s surface. 
Phil. Mag. (Taylor), v, 1829,24-28,106-109. 
Showing what he calls an error in the method of com 
puting difference of longitude used by the trigono 
metrical survey of Great Britain. 
Some arguments tending to prove that the earth 
is a solid of revolution. 
Phil. Mag. (Taylor), v, 1829,205-209. 
The most probable inference that we can at present 
draw from the best measurements that have been 
made is that the meridians are equal and similar 
ellipses. 
Letter relating to the figure of the earth. 
Phil. Mag. (Taylor), vu, 1830, 241-244, 412-416. 
Stating the insufficiency of Clairaut’s theory, as it is 
universally taught and applied, for finding the fig 
ure of equilibrium of a homogeneous planet, supposed 
fluid. 
On the figure of the earth. 
Phil. Mag. (Taylor), vu, 1830, 412-416. 
A discussion of the theory advanced by Biot and pub 
lished in Mémoires de l’Académie des sciences, vm, 
1829. 
A direct method of finding the shortest distance 
between two points on the earth’s surface when their 
geographical position is given. 
Phil. Mag. (Taylor), vin, 1830, 30-34. 
J, Survey of the coast of the United States. 
Merchant’s Mag, (Hunt), 1849, 131-149,