g 
S 
SABINE’S EXPERIMENTS. 
: EXPERIMENTS IN LONDON. 
The. corresponding experiments in London were made in March and in 
the beginning of April, 1823, in the house of Henry Browne, Esq. F. R. 8. 
in Portland Place, in the same room in which Captain Kater determined the 
length of the pendulum in 1817. The same agate support for the knife-edge 
of the pendulum which had been used at New-York, was here firmly screwed 
to the mahogany plank which had supported Captain Kater’s pendulum ; 
every other part of the apparatus used in London, was the same as at New- 
York, except the Astronomical Clock, which of course is immaterial to the 
result; the general temperature of the apartment underwent much the same 
variation in amount in the course of the 24 hours as at New-York, except on 
the 11th and 13th of March, when the room was purposely heated by char- 
coal, in order to obtain results at a considerable difference of temperature. 
The rate of the clock was supplied by Mr. Browne, from its comparison 
with two other clocks of great excellence ; one of which, by Cumming, is well 
_ known by its service in former pendulum experiments, and the other has been 
recently made on the same construction by Mr. Molyneux, and has proved 
not inferior to the original: these clocks are regularly compared with Astro- 
nomical time, by a transit instrument. The clock used in the observations of 
coincidences was made by Bolton, and its rate during the period in which 
they were continued, was deduced as follows. 
