F 9
The ball was dropped successfully 359 times. There were two failures. On May 23, on hoisting the ball it was found that the shaft had worked loose in its plunger, and it was considered unadvisable to allow the ball to fall until the necessary repairs had been effected. On December 23 the lock failed to discharge owing to incorrect tension of one of the springs.
The apparatus was under repair on January 29, and from May 25 to 28.
The ball fell with an error of 0.3 or less on 332 occasions, and with an error of 0.4 or 0.5 on 20 occasions. Errors of 0.6, 0.7, 0.9, 1.0, and 1.2 occurred once, and of 0.8 twice.
The probable error of the Time Ball for the whole year, 0.14, was the smallest on record. The monthly values for the past five years were as follows:-
Month 1912 1913 1914 1915 1916 January, ±0.33 +0.20 ±0.18 +0.17 ±0.15 February, .25 .21 .15 .44 .28 March, .14 .54 .21 .17 .17 April, .13 .21 .22 .38 .18 May, .11 .11 .25 .16 .10 June, .18 .10 .16 .15 .17 July... .13 .17 .20 .17 .10 August, .12 .15 .21 .15 .10 September, .16 .10 .14 .13 .11 October, .12 .12 .14 .10 .13 November, .21 .17 .13 .16 .13 December, .27 .26 .28 .14 .11 Means, +0.18 ±0.20 ±0.19 +0.19 ±0.14Transit Instrument. - Observations for time were made daily with the 3-inch transit instrument and the Hipp tape chronograph by the Chinese computers, weather permitting.
The number of observations in the years 1915 and 1916 were as follows:-
1915 1916 Transits, 1,817 1,778 Level determinations, 854 890 Azimuth determinations, 32 34 Collimation determinations, 30 33Transits of the sun were only observed when star transits were not available from the previous night.
The azimuth and collimation determinations were made by the Director, the Chief Assistant, and the First Assistant. The azimuth determinations depend usually on observations of the old south mark.
F 9
The ball was dropped successfully 359 times. There were two failures. On May 23, on hoisting the ball it was found that the shaft had worked loose in its plunger, and it was considered unadvis- able to allow the ball to fall until the necessary repairs had been effected. On December 23 the lock failed to discharge owing to in- correct tension of one of the springs.
The apparatus was under repair on January 29, and from May 25 to 28.
The ball fell with an error of 03 or less on 332 occasions, and with an error of 04 or 05 on 20 occasions. Errors of 06, 0°7, 09, 10, and 1-2 occurred once, and of 08 twice.
The probable error of the Time Ball for the whole year, 014, was the smallest on record. The monthly values for the past five years were as follows:-
Month.
Probable error of Time Ball.
1912
1913
1914
1915
1916
January,
±0.33
+0*20
±0.18
+0'17
±0.15
February,
25
'21
*15
44
*28
March,
*14
'54
*21
*17
*17
April,
13
'21
*22
*38
18
May,
11
'I I
*25
•16
'10
June,
*18
*10
*16
*15
*17
July...
13
*17
-20
'17
'10
August,
+
12
'15
'21
*15
*10
September,
'16
'10
'14
13
'I I
October,
*12
'12
•14
'IO
13
November,
*21
'17
13
16
13
December,
*27
*26
•28
14
'I I
Means,
+0.18
±0.20
±0.19
+0.19
±0.14
Transit Instrument. - Observations for time were made daily with the 3-inch transit instrument and the Hipp tape chronograph by the Chinese computers, weather permitting.
The number of observations in the years 1915 and 1916 were as follows:-
Transits,
Level determinations,...
Azimuth determinations,
Collimation determinations,
1915. 1916.
.1,817 1,778 854 890
32 34
30
33
Transits of the sun were only observed when star transits were not available from the previous night.
The azimuth and collimation determinations were made by the Director, the Chief Assistant, and the First Assistant. The azimuth determinations depend usually on observations of the old south mark.
No comments yet.
Private notes are available after approval.