WILLIAM HARKNESS. 
293 
sufficiently to permit his return to Washington to complete 
various pieces of scientific work. His energy and faithful¬ 
ness should be emulated by all. His example should spur 
us on to greater faithfulness, activity, and zeal in carrying 
on labors commenced by him and providentially committed 
to us to continue.” 
William Harkness was a man of the highest moral prin¬ 
ciples, hating sham in science, in society, and in the state, 
and freely expressing his appreciation of truth as he saw it. 
He was endowed with a mind of unusual penetration which 
went to the heart of scientific and social problems with un¬ 
erring precision, and his memory of details and facts made 
his suggestions as to their connection with general principles 
valuable and instructive. His own tastes led him to pursue 
astronomy rather more on the practical side than on the 
theoretical, and he was concerned with devising and con¬ 
structing instruments of precision more than in developing 
the analytical formulae of the subject. He was a mathema¬ 
tician of ability, as his numerous memoirs demonstrate, but 
he was especially pleased to discover the formula which con¬ 
tained exactly the mechanical dimensions and the physical 
process in compact form. 
His work on the “ Solar parallax and its related constants,” 
in which are correlated the numerous determinations of the 
constantslof the solar system, and his theory of the focal 
curve of achromatic telescopes are probably best known to 
science in general. At the Observatory there is hardly a 
piece of apparatus in use at the present time which is not 
either the work of his mind or which does not embody 
essential features which he suggested. He drew up the 
specifications for constructing the 12-inch equatorial tele¬ 
scope and for remounting the 26-inch equatorial, the 8.5-incli 
transit circle, the meridian transit, and the prime vertical 
transit in 1891, for constructing the new 6-inch steel transit 
circle in 1894, and the 5-inch steel alt-azimuth in 1895. In 
these instruments dials were introduced and placed con¬ 
veniently near the observer to indicate the position of the 
41—Bull. Phil. Soc., Wash., Vol. 14, 
