Sydney Observatory Papers No.31
SYDNEY OBSERVATORY : 1858 to 1958 Part 7
By HARLEY WOOD
WILLIAM ERNEST COOKE
William Ernest Cooke was born on 1863, July 25, in Adelaide. After
graduating from Adelaide University he was attached to Adelaide
Observatory. When Perth Observatory was founded in 1896 he was
appointed first director and was successful in developing the work on
the Astrographic Catalogue. In 1912 he was appointed Government
Astronomer for New South Wales and Professor of Astronomy at the
University of Sydney.
Cooke was offered the opportunity to reorganise the work of the
Observatory and to move to a better position. A site selected by T.
W. E. David, James Nangle and Cooke, was acquired about half a mile
east of Wahroonga Railway station. [pg. 20]
This was regarded as being far enough out of the city to avoid the
worst effects of haze and light in the sky but close enough to make
University and public contacts reasonably possible. Among the pieces
of equipment planned for the reconstructed Observatory were a mirror
transit to make possible observation of fainter stars and a
reflecting telescope of an aperture about twenty four inches. He
planned to begin fundamental transit work as recommended by the
meeting of the Commite’ International
permanent pour l’Execution de la’Carte photographique du Ciel in 1909. Cooke
devoted much energy to all this planning but the 1914-18 War caused
it to be postponed indefinitely in 1916 and despite all his efforts
he was unable to revive it. Several attempts failed, too, to bring
about his projected tour of inspection of observatories in Europe and
America.
As a preliminary it was necessary to assess the twenty years’ work already done on the Astrographic
Catalogue. Before he arrived Cooke asked Raymond to prepare a list of
positions of stars with meridian observations and found that,
contrary to his previous impression, there were not enough positions
of reference stars available reduction of the photographic plates of
the Catalogue. He decided to reorganise the transit work by observing
strictly in accordance with the recommendations made at the 1909
meeting of the Comite' permanent de la Carte du Ciel. According to
this plan the lists of stars were to be observed strictly
differentially relative to selected stars for which fundamental
observations were obtained. His methods of observing and of reducing
the observations, described two papers in Monthly Notices of the
Royal Astronomical Society and in the “Catalogue of 1068 Intermediate Stars” enabled the output to be much increased and
the reductions to be kept right up to date. The first observations of
the programme began in March, 1918, on the intermediate stars of our
astrographic zone −51° to −65°. By June, 1921,
this work was complete including discussion of pivot errors, circle
errors and personal equations, and the “Catalogue of 1068 Immediate Stars” was printed and distributed in 1922. Work
was immediately begun on the reference stars for the reduction of the
plates of Astrographic Catalogue. These observations were made in
zones two degrees wide differentially relative to theintermediate
stars. The zone from −51°to −57° was finished
in catalogue form by March, 1922, and that for −53° to
−55° in 1923. These two catalogues have not been
published.
The difficulty of making meridian observations of the faint stars
which had to be observed in order to yield enough reference start for
the astrographic work led Cooke to develop ideas for obtaining a
large aperture by designing a mirror transit but he is-as unable to
obtain resources to have it made.
In 1922, when Schlesinger, of Yale University Observatory,
received the “Catalogue of 1068
Stars” he wrote to Cooke to suggest the
other southern zones might be observed in the same way. He was
engaged in the determination of star places using photographs in wide
angle and said that he hoped to use intermediate stars as the basis.
Cooke undertook to observe the zone −30° to
−51° thus links up with work reaching to −30°,
which was being done at the United States Naval Observatory. The
observations were made in I923 and 1924 but the catalogue was
published on only in 1949 as “Sydney
Observatory Papers, No. 8” Out of the
correspondence Schlesinger arose the suggestion that the plates of
the southern zone corresponding to our astrographic section should be
measured at Sydney. The difficulty of obtaining a sufficient number
of suitable reference stars for the Catalogue would be this solved.
This was agreed and Cooke set about equipping himself with rather
formidable measuring machine required to measure plates of dimensions
nineteen inches by twenty three inches. Cooke’s term of ended before this scheme bore
anyfruit. [pg. 21]
In December, 1914, Cooke asked for the appointment of a Board of
Visitors to the Observatory “to take a
general oversight and interest” in its
work and to offer advice to the Government on matters affecting the
Observatory. The previous “Observatory
Board” of Russell's time had, according
to Lenehan lapsed because of lack of a quorum for meetings. Cooke's
recommendation was approved and the Board first met on 1916, August
16. Subsequent experience has shown the Board of Visitors to be a
valuable adjunct to the 0bservatory. At the first meeting of the
Board Cooke expressed doubt as to the value of much of the
photographic work already done for the astrographic Catalogue because
he thought that variation of procedures which had occurred since the
beginning would stand in the way of using the material to determine
magnitudes or the distribution of the stars according to magnitude.
Actually the needs of this work are different from what they appeared
to be when the astrographic programme was designed and the
astrographic material is not suitable for determining magnitudes.
Cooke did, however, recognise that the plates were valuable for study
of stellar motions and later, using plates of epoch difference ten
years or more, co-operated in this work with Innes, Director of the
Union Observatory. When, at the Board’s
request, Cooke referred his doubts to the Astronomer Royal Dyson's
recommendation was to prepare for publication the measures already
made. This Cooke proceeded to do with commendable energy. The Board
also recommended, that, if the move to Wahroonga was not to take
place, arrangements should be made for the Government Astronomer to
reside at the Observatory. The Weather Bureau moved out of the
residence which it had occupied since the separation in 1908 and
Cooke, in his report of 1917, commented on the value of his residence
on the spot for his Observatory work and for the practical classes
with his University students.
Soon after his appointment Cooke had decided that he preferred to
make measurements of the astrographic plates at Sydney and ordered a
machine for measuring rectangular co-ordinates of the stars on the
plates. The Turner pattern arrived in 1915 and he had some and has
some clerical staff appointed to make measures and to assist in
preparing the manuscript of the Catalogue. Another machine was later
added and the measurement was accelerated. He made some improvements
to the astrograph, standardised the exposures and the processing of
the plates and, as a check on the transparency of the atmosphere,
began regular photography of the area around the south celestial pole
along with the plates for the Catalogue. For magnitude purposes he
arranged a graduated series of star images in the eyepiece of each
measuring machine with which the image of each star was was compared
as it was being measured. The magnitude values of these scales were
determined by photographic of the standard areas (E regions) at
declination at -45°. By 1925, despite several postponements
while he was obtaining finds, there were six volumes of the Catalogue
published. The installation of the apparatus for the work and the
publication of these first results thus determined the form since
followed for the Sydney Section of the Astrographic Catalogue.
Cooke was very much interested in time signals and longitude
determination, on which he published several papers. By February,
1913, he was suggesting that accurate time should be made available
to telephone subscribers by connecting a clock in the Observatory to
a sounder which could be connected to the telephone system. This
service to telephone subscribers was arranged in 1914 and remained
inthe same form until 1954. The introduction of the wireless time
signals for navigation which he suggested at the same time did not
occur until 1924.
For want of financial support Cooke was compelled to drop an
extensive plan to determine longitudes in the Pacific in 1916 but the
subject arose again in connection with the fixing of the boundary
between South Australia and Western Australia [pg. 22] on the 129th
meridian, when it was hoped by an accurate determination to avoid
kind of difficulties that had earlier led to the expensive litigation
about the boundary between Victoria and South Australia. With the
co-operation of the Astronomers Royal of England and Scotland and of
General Ferrie' Director of French Radio System, and others, a series
of experiments was conducted to find time transmissions which could
be heard in both Greenwich and Sydney. The signals from Lyons proving
most suitable a series of observations in co-operation with the
French and English authorities in 1921, April and May, gave the
longitude of Sydney 10h 4m 48.98′ east of
Greenwich. Cooke continued his experiments on reception of wireless
time signals even after this programme was complete since he thought
that the views of astronomers here important because of the long
paths the signals had to follow to reach this part of the world.
The total solar eclipse of 1922, September 21, aroused a great
deal of interest among Australian astronomers, both professional and
amateur, and brought observing expeditions here from abroad. With the
support of the Board of Visitors Cooke obtained approval to move the
astrograph to Goondiwindi in Queensland. Bad atmospheric definition
and poor performance of the driving clock of the telescope led to
failure of an attempt to measure the deflection of starlight passing
near the Sun for comparison with the value predicted by Einstein’s Theory of Relativity but the times of the
contacts were observed, both by eye and by measurement of a series of
timed photographs, and at Grafton the southern edge of the Moon’s shadow was fixed by a line of
observers.
Of several minor activities his interest in sundials seems most
important. He published original designs for home construction and in
1924 patented an improvements intended for commercial production
which would undoubtedly have been success but for the introduction of
radio time signals.
At Sydney University, Cooke, from 1914 onwards, gave a course for
second year students with a gradually increasing, though never large,
of students. He also carried on adult education classes for the
Department of Tutorial Classes of the University, including several
lecturer tours of country centres. His students remember him with
respect and attention. This valuable association with the University
terminated with Cooke’s retirement.
In October, 1925, a very strong recommendation by Cooke in favour
of the move to Wahroonga was brought before the State Cabinet who at
first decided that they would close the Observatory, rather than bear
the expense of moving and re-equipping it but representations by the
Board of Visitors of the Observatory, the Royal Society of New South
Wales, the New South Wales Branch of the BritishAstronomical
Association and Sydney University caused to modify this decision and
agree at first to continue only the time service but later, on a much
reduced scale, the work of the Astrographic Catalogue, an
international obligation. Cooke, who was close to the retiring age,
left the Observatory on 1926, August 31, and most of the staff of the
Observatory was transferred to other Departments.
Those people who had best opportunity to know Cooke respected him
as a man and as an Astronomer but he did not always work well within
the restrictions of the Public Service and felt frustrated by the
failure to carry out the reorganisation he had expected when he came.
W. E. Raymond and H. C. Cranney who were engaged on the transit
programme, undertaken during the second part of his period here put
forth tremendous efforts which speak unmistakable for the inspiration
he was able to give them. After his retirement Cooke returned to
Adelaide to lived and died there on 1947, November 7 [pg. 23]
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