TRANSACTIONS OF SECTION A. $11 
our Association for the Advancement of Science may pause for a moment to gaze 
upon the vision revealed three centuries ago in the ‘Advancement of Learning’ by 
a philosopher whose influence upon the thought of the world is one of the glories 
of our nation. 
I have implied that Bacen’s discourse was in advance of its age, so far as Eng- 
land was concerned. Individuals could make their mark in isolated fashion, Thus 
Harvey, in his hospital work in London, discovered the circulation of the blood ; 
Napier, away on his Scottish estates, invented logarithms; and Horrocks, in the 
seclusion of a Lancashire curacy, was the first to observe a transit of Venus. 
But for more than half a century the growth of physical science was mainly due to 
workers on the continent of Kurope. Galileo was making discoveries in the 
mechanics of solids and fluids, and, specially, he was building on a firm founda- 
tion the fabric of the system of astronomy, hazarded nearly a century before by 
Copernicus ; he still was to furnish, by bitter experience, one of the most striking 
examples in the history of the world that truth is stronger than dogma. Kepler 
was gradually elucidating the Jaws of planetary motion, of which such significant 
use was made later by Newton; and Descartes, by his creation of analytical 
geometry, was yet to effect such a constructive revolution in mathematics that 
he might not unfairly be called the founder of modern mathematics. In England 
the times were out of scientific joint: the political distractions of the Stuart 
troubles, and the narrow theological bitterness of the Commonwealth, made a 
poor atmosphere for the progress of scientific learning, which was confined almost 
to a faithful few. The fidelity of those few, however, had its reward; it was 
owing to their steady confidence and to their initiative that the Royal Society of 
London was founded in 1662 by Charles II. At that epoch, science (to quote 
the words of a picturesque historian) became the fashion of the day. Great 
Britain began to contribute at least her fitting share to the growing knowledge of 
Nature; and her scientific activity in the closing part of the seventeenth century 
was a realisation, wonderful and practical, of a part of Bacon’s dream. Undoubtedly 
the most striking contribution made in that period is Newton’s theory of gravitation, 
as expounded in his ‘ Principia,’ published in 1687. 
at century also saw the discovery of the fluxional calculus by Newton, and 
of the differential calculus by Leibnitz. These discoveries provided the material 
for one of the longest and most deadening controversies as to priority in all the 
long history of those tediously barren occupations ; unfortunately they are dear 
to minds which cannot understand that a discovery should be used, developed, 
amplified, but should not be a cause of envy, quarrel, or controversy. Let me 
say, incidentally, that the controversy had a malign influence upon the study ot 
mathematics as pursued in England. 
Also, the undulatory theory of light found its first systematic, if incomplete, 
exposition in the work of Huygens before the century was out. But Newton had 
an emission theory of his own, and so the undulatory theory of Huygens found 
no favour in England until rather more than a hundred years later; the researches 
of Thomas Young established it on a firm foundation. 
Having thus noted some part of the stir in scientific life which marked 
the late years of the seventeenth century, let me pass to the second of our 
centenaries: it belongs to the name of Edmund Halley. Quite independently 
of his achievement connected with the year 1705 to which I am about to refer, 
there are special reasons for honouring Halley’s name in this section at our 
meeting in South Africa. When a young man of twenty-one he left England for 
St. Helena, and there, in the years 1676-1678, he laid the foundations of ‘stellar 
astronomy for the Southern Hemisphere ; moreover, in the course of his work he 
_ there succeeded in securing the first complete observation of a transit of Mercury. 
After his return to England, the next few years of his life were spent in 
‘laying science under a special debt that can hardly be over-appreciated. He 
placed himself in personal relation with Newton, propounded to him questions 
_and offered information ; and it is now a commonplace statement that Halley's 
a questions and suggestions caused Newton to write the ‘ Principia.’ More than 
this, we know that Newton's great treatise saw the light only through Halley s 
