After a glowing reference from his headmaster, he took a Civil Service cadetship under Sir Charles Todd at the Adelaide Observatory in December 1878.

Cooke married Jessie Elizabeth Greayer in Adelaide in 1887 and they had six children—five before arriving in Western Australia: Violet Ogden (1888), Lionel Ernest (1889), Rosalie (1891, died in infancy), Frank Basil (1892), and Erica Carrington (1894).

In December 1894 he wrote to Forrest advising that the £3,000 which had been set aside in the budgets for construction was sufficient and would be adequate for the purchase of instruments also.

The appointment of an astronomer of course requires very careful consideration and I am glad to call your attention to Mr W. E. Cooke, M.A., my first Assistant who would, I have reason to know, accept the office if offered it.

Mr Cooke has been employed in the observatory here, under my direction, for about 13 years, and has full experience in all Astronomical and Meteorological work.

He is about 32 or 33 years of age, and therefore in the full vigour of young manhood – he is very zealous in his work, very steady, and high principled, and is married.

[2]The foundation stone was laid by Forrest on 29 September 1896 and the Observatory was completed at a cost of £6,622, more than double the estimate, on 3 March 1897.

Weather data was transmitted from the country stations twice a day to the General Post Office in Perth by telegraph.

[3] With the catalogue, Cooke produced a critique of the international programme, referring to lack of coordination, refinements that he had made in observation methods and suggested procedures to be used at other sites around the world.

The catalogues proposed were: Cooke attended the International Astrographic Conference in Paris in 1909 where he presented his ideas and which were accepted by the congress.

In 1912 Cooke departed Western Australia and took a position as government astronomer in New South Wales and Professor of Astronomy at the University of Sydney.

[5] The government pushed for its closure in 1926 but was narrowly defeated after a bitter opposition campaign, however Cooke became the political scapegoat and was forced into early retirement in the same year.