388 
plates is well advanced, and in the report the 
parallaxes of seven stars have been determined and 
indicate the high standard obtained. 
Photographic magnitudes determined with the 6-in. 
astrographic triplet are next dealt with and we notice 
that great progress has been made with the work in 
hand. The same may be said of the work on the photo- 
graphic magnitudes with the 26-in. refractor on the 
Kapteyn areas and the central regions of the Franklin- 
Adams charts, and of the astrographic equatorial for the 
determination of photographic magnitudes of stars in 
the Greenwich section of the Astrographic Catalogue 
by comparison with the standard magnitudes of the 
stars round the north pole. 
With regard to heliographic observations, photo- 
graphs of the sun were secured on 258 days, and of 
these 515 have been selected for preservation. Photo- 
graphs were received from the Royal Observatory, 
Cape of Good Hope, to March 1, 1914; from Dehra 
Din, India, to December 7, 1913, and from Kodai- 
kanal, India, to December 13, 1913, the series for the 
year 1913 being made up from the four contributing 
observations. The mean daily spotted area of the sun 
has been eight millionths of the sun’s visible hemi- 
sphere during 1913, as against thirty-seven in 1912, 
and sixty-four in 1911. The appearance of a moderately 
large spot in March pointed to the end of this very iow 
minimum of solar activity. 
An expedition is in preparation to proceed to Minsk, 
in Russia, to observe the total solar eclipse visible on 
August 20-21. The programme is stated to be similar 
to that attempted in Brazil in 1912. 
Coming now to the magnetic observations, we find 
that the mean values of the magnetic elements for 
1913 and three previous years from observations in the 
magnetic pavilion are as follows :— 
Declina- Horizontal force Dip (3-inch 
Year tion W. in C.G.S units needles) 
° ‘ ° rf “ 
NGUO! Gs LS 4ac2 018532 66 5257 
MGWIE gan SBR) 0-18529 66 52 
1O E25 24-8 0:18528 66 51 46 
UO sae Sigel 0-185 14. 66 50 27 
In 1913 there were no days of great magnetic dis- 
turbance; one day was classified as of lesser disturb- 
ance. The new magnetic house being now complete, 
will shortly receive the new instruments to be set up 
in it; these are briefly described in the report. 
A short résumé regarding the present state of the 
meteorological reductions is followed by a summary 
of the weather conditions for the period covered by this 
report. 
The mean temperature for the year 1913 was 50:5°, 
or 1-0° above the average of the seventy years, 1841- 
tgt0. Kor the twelve months ended April 30, 1914, 
the mean temperature was 508°. During the twelve 
months ended April 30, 1914, the highest temperature 
in the shade (recorded on the open stand in the enclo- 
sure of the magnetic pavilion) was 87-1° on June 17. 
On eight days the highest temperature in the shade 
equalled or exceeded 80°, but five of these days occurred 
in May and none in July. The lowest temperature of 
the air recorded during the same period was 19-9° on 
January 24. 
The mean daily horizontal movement of the air in 
the year ended April 30, 1914, was 288 miles, which is 
four miles above the average of the previous forty-six 
years. The greatest recorded daily movement was 
759 miles on April 6, and the least seventy-nine miles 
on October 24. The greatest recorded pressure to the 
square foot was 26:0 Ib. on December 26, and the 
greatest velocity in an hour forty-four miles on March 
16 and April 6. 
The number of hours of bright sunshine recorde® 
during the twelve months ended April 30, 1914, by the 
NO: 2328, VOL» 03] 
NATORE 
[June tr, 114 
Campbell-Stokes instrument, was 1446 out of a pos- 
sible 4457 hours, giving a mean. proportion of 0-325, 
constant sunshine being represented by 1. This is not 
far below the average amount, a very fine April nearly 
counterbalancing an exceedingly dull July. 
The rainfall for the year ended April 30, 1914, was 
22-30 in., being 1-82 in. less than the average for 
the period 1841-1905. The number of rainy days 
(0-005 in. or above) was 164. January with o-50 in. 
was the driest month, and March with 3-93 in. the 
wettest. 
The sections dealing with the chronometers, clocks, 
and time service indicate a considerable state of 
activity. Thus under the first-named, it is stated that 
in the year ended May 10, 1914, the average daily 
number of chronometers and watches being rated was 
712, the total number received was 2094, the total 
number issued was 2110, and the number sent to 
repair 934. 
An interesting table is that showing the times sent 
out from the time-distributing centres, namely, the 
Eiffel Tower and Norddeich, as recorded at the ob- 
servatory. These signals are regularly received and 
compared: with the Greenwich time. The results to 
May 10, 1914, using the impersonal micrometer of the 
altazimuth as the standard for the personal equations 
of the Greenwich observers, are as follows :— 
Eiffel Tower. 
No. of Signallate Personal Mean dis- 
PServer obs. on G.M.T. — equation cordance 
Ss. Ss. s. 
L (Morn.) .. Jon 94D 0 002 _- +0-110 
WB (Morn.) - -.. .§39 0 044 —- tO-114 
eee st BTS — —0:057 + 0-060 
Rhythmic signals 175 0-041 — +0-065 
W B (Night) >. 256 0-050 — + 0-122 
Norddeich. 
Morn.) ... .2 e880 0-016 _- 0-225 
WeBe(Morn.) ... 526 0-060 --- + 0-209 
L—W BB ..... So) OO — —0:051 +0:075 
Rhythmic signals — — — — 
WeB (Night) ... 242 0-062 — +0:214 
In the Astronomer Royal’s general and concluding 
remarks he states:—‘‘The excellent spirit which 
animates both the permanent and temporary staff of 
the observatory is shown by the large number of 
observations and by the extent to which measurements, 
computations, and other work are kept up to date. 
Attention may be directed to the improvement in the 
altazimuth observations by the introduction of the 
impersonal micrometer and new eye-end to the instru- 
ment, to the success which has so far attended the 
observations for stellar parallax, and to the changes 
which are in progress in the magnetic observations.” 
The reader shou'd be reminded that the above brief 
summary of the Astronomer Royal’s report to the 
Board of Visitors only conveys a very general idea of 
the work carried on during the past year. anites 
original report should undoubtedly be read to gain a 
proper indication of the great amount of work sum- 
marised in the brief but concise paragraphs which 
compose it. 
THE DEVELOPMENTAOFP THE 
AEROPLANE.! 
R. GLAZEBROOK dealt mainly with the work of 
experiment and scientific research in the develop- 
ment of the aeroplane, referring especially to the work 
of Dr. Stanton, Mr. Bairstow, and their coileagues 
at the National Physical Laboratory. The experi- 
ments are conducted in an air channel in which a 
1 Abstract of the second Wilbur Wright Memorial Lecture, delivered 
before the A-ronautical Society of Great Britain on May 20, by Dr. R. T. 
Glazebrook, C.B., F.R.S. 
