3
133
14. As stated in the time-ball notice published in the Government Gazette on the 10th January, 1885, the ball is not dropped on Sundays and on Government Holidays. The ball was dropped every working day in the past year except on the 17th, 19th, and 26th May and 26th June when it was not hoisted on account of thunderstorms, and on the 8th August the mast was found split, where two pieces were riveted together. The ball could not be hoisted on the 8th, 9th and 10th of that month, while under repair by the Public Works Department. There was not a single failure during the year.
TABLE II.
Errors of Time Ball in 1888.
means too late.
+ means too early.
Date.
Jan. Feb.
March. April. | May.
June.
July.
Aug.
Sept. Oct. Νοτ. Dec.
1,
+
-0.'4 +0.52 -0.6 +0.3
0.'1
0."1
+0.5
0,"1
0. 1
0.1
0.1
+0.6
3,
-0.3
-0.8
+0.3
+0.5
0.1
...
0.1
0.1
-0.2
0.'1 +0:2
0.1 +0.2
0,"1 -0.2
0."1
0.1
4,
-0.5
0.1
+0.6
0.1
+0.2
0.1
0.1 0.1
0.1
-0.2
5,
0.1
+0.4
+0.6
0. 1
0.1
-0.2
---
0.1 -0.2
0.1
-0.2
6,
0.1
0.1
+0.5 +0.7
0.1
0.1
7,
0. 1
0.1
+0.5
+0.8
0. 1
0, 1
0.1
-0.3
+0.2 -0.2 +0.2
0.1 0.1
+0.2
0.1
8,
0.1
+0.3
0.1
0.1
+0.3 -0.4
+0.3 0.1
9,
0.1
0.1
+0.4
+1.0
0.1
0.1
0.1
-0.5
+0.4
10,
0.1
0.1
+0.5
+1. I
0.1
-0.2
0.1
-0.6
+0.6
+0.2
11,
+0.2
0.1
+1.2
0.1
.0.1
-0.2 +0.3
0.1
0.1
0.1
12,
0.1
+0.7
+1.3
0.1
0.1
0.1
+0.2
0.1
+0.3
0.1
13,
0.1
0.1 +1.5
0.1
0.1
0.1
+0.3
0.1
0. I
0.1
14,
0.1
+0.3
+0.3
0.1
0.1
0. 1
0.1
0.1
0.1
-0.2
0. 1
15,
+0.3
+0.4
+0.2
0.1
0.1
-0.2
0.1
-0.3
0.1
16,
0. 1
+0.4
+0.5 +0:3
+0.2
0.1
+0.2
0, 1
1+0
0.1
0. 1
17,
0.1
+0.4
+0.6
+0.3
+0.2
0.1
-0.4
0.1
0.1
+0.2
18,
0.1 +0.5
+0.4 0.1
+0.3
0.1
0.1
-0.5
0.1
+0.8
19,
0.1
0.1
+0.2
+0.4
0.1
0.1
0.1
0.1
+0.6
20,
0.1
0.1
0.
+0.2
0.1
0.1
0.1
0.1
0.1
0.1
+0.7
21,
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
-0.2
22,
0.1
0.1
+0.4
-0.2
0.1
0.1
0.1
0.1
0.1
23,
0.1
-0.2
0.1
-0.2
+0.
-0.3
-0.2
0.1
0.1
0.1
24,
0.1
-0.2
0. 1
0.1
+++
-0.3 -0.2
0.1
-0.3
-0.2
25,
0. 1
0.1
-0.2
+1.5-0.2 0.1 -0.2
0.1
0.1
26,
0.1
0.1
0.1
0.1
0.1
0.1
0.1
27,
0.1
0.1
+0.2
0.1
-0.3
0.1 -0.3
0.1
0.1
0.1 -0.5
28,
0.1
0.1
+0.2
0.1
29,
A
+0.2
+0.3
...
0. 1
0. 1 -0.2
0.1
0.1
+0.4
0.1
+0.7 -0.3 0.1 0.1 +0.3 +0.4
0.1
-0.6
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
30,
31,
15. The probable errors of the signal in the different months of 1888 (with the average percentage of clouded sky added in parenthesis) were as follows:-January 0.12 (48), February 0.19 (85), March 0.26 (91), April 0.41 (86), May 0.20 (84), June 0.14 (92), July 03.13 (59), August 0o.17 (60), September 0.14 (57), October 0.14 (53), November 0.15 (48), December 0.17(56).-The mean of the probable errors was 0.18. A new standard clock with mercurial compensation has been ordered from England. When that arrives and is erected and rated the errors will be reduced during periods of persistently overcast weather (on the 14th April last year the sun was observed after 20 days of continually overcast skies). It will then have to be decided whether it would not be as well to cut a certain quantity off the zinc rod, say a length corresponding to three-quarters of the temperature co-efficient, for no matter how well this is determined, the rate will ceteris paribus be more regular the more perfectly the clock is compensated.
16. With reference to a suggestion made concerning tidal and magnetic observations in the 5th paragraph of my last Annual Report, the Secretary of State did not assent to any discontinuation of the magnetic observations, which are ordered to be continued as heretofore. It is intended to re-inves- tigate the induction coefficient of the vibrating magnet next spring. It does not appear that any im- provement could be effected in Mr. ROBERTS's tide-tables (which represent the tides very closely indeed) by aid of the amount of trace available at present from the automatic tide-gauge, but next year when three years' trace is available would be the time to have it harmonically analyzed.
17. The following papers have been published in Europe in the course of the past year:-
Telegraphic determination of the longitude of Haiphong" (Month. Not. R.A.S. Vol. XLVIII
No. 5). "On comet seeking" (Journ. Liverpool Astr. Soc. Vol. VI No. 7).
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