F 16
In the following table is given the excess of the observed error of Dent No. 39741 over the computed error during cloudy periods in 1924 :-
Date 1924 Interval without observations Excess of observed over computed error January 9 16 28 2 days 19 26 27 + 0'09 March 3 9 + 0'37 21 27 + 0.38 9 19 0'03 21 25 + 0.10 April 3 + 0'24 May 4 8 + 0.03 17 24.... 31 — 0*370°32
+ 0.27
+ 0.40
+ 0.77
+ 0.10 June 3 4 + 0.43 July 16 22 + 0.25 25 29 + 0.09 August September 13 19 + 0.98
+ 0.66 October 17 3 17 + 0.10 17 27 + 0.32 27 + 0.46 November 2 4 + 0.02 23 0*23 December 7 + 0.02
+ 0.25
0'13
O'20
+ 0.31
+ 0°24
+ 0·40
+ 0.37
The new Sidereal clock (Cottingham and Mercer No. 507) was received on December 12. It is of the Cottingham type and was constructed by Mr. Thomas Mercer of St. Albans. The pendulum and movement are enclosed in an hermetically sealed case in which the pressure of the air can be regulated as desired. Driving power is supplied by a gravity arm remounted electrically every 36 seconds. At the termination of the year 1924, adjustments were in progress. It is hoped to bring the clock into regular use early in 1925, and to take the opportunity of thoroughly overhauling Dent No. 39741.