218 Transactions of the Boyal Society of South Africa. 
Belopolsky, and Pickering opened up an entirely new world of discovery, 
it was a profound regret to him that his equipment at the Cape Observatory 
hindered his taking an active, if not leading, part in the new enterprise. 
In 1894, however, the offer of a magnificent 24-inch photographic 
refracting telescope, with all the necessary spectroscopic mountings, on the 
part of Frank McClean, Tunbridge Wells, opened up the way to astro- 
physical research at the Cape. 
Towards the close of 1898 the telescope, with the whole of the 
essentials of the observatory, was in full working order, but it was not 
till 1901 that work was begun, owing to certain corrections which had to 
be made in the object-glass. From this year to the close of 1906 it was 
constantly used, under the direction of Gill, to determine the spectra of 
stars, of rare metals, as well as motion in the line of sight. 
In the fitting up of this astrophysical telescope Gill took the keenest 
interest. It absorbed his whole energies for some years. At its erection 
he was mason, joiner^ engineer, and handy man. 
We have to leave many of his other interesting activities unrelated 
except in name — his detection and definition of the relation of brightness 
to transits, his determination of circum-polar places, his interest in the 
magnetic survey of South Africa, his inquiry into the diurnal range of 
temperature as affected by thermometer screens, an examination of the 
spectrum of Eta Argus, besides a constant inquiry into instrumental 
adjustments, on the wear of screws, on the simplification of clock 
machinery, on the housing of telescopes. 
This enumeration alone will indicate, in some measure, the range of 
his mind and the scope of his energies. 
Gill's tenure of office at the Cape Observatory was rounded off by two 
most interesting visits from astronomers and scientists outside the Colony. 
In 1882 there occurred the Transit of Venus, and this brought a number 
of well-known observers to South Africa. Among them was Simon New- 
comb, the most notable of American astronomers and mathematicians. 
Between him and Gill a deep friendship sprang up, which continued 
unbroken and unshadowed till Newcomb's death. This friendship had a 
definite influence on both men. It made Newxomb more practical in 
his thoughts and undertakings; it made Gill, if possible, more severe 
and exhaustive in his consideration of the theoretical aspects of an 
investigation. 
At Newcomb's request, first conveyed by letter in 1879, Gill undertook 
a series of observations of lunar occupations in order to obtain more 
accurate constants for the lunar theory. Between the years 1881-1906 
no fewer than 1946 occupations were secured. 
The other interesting visit was that of the British x\ssociation in 
1905, one year before Gill's retirement. Perhaps to Gill the brightest, 
