8 
times might well have been made a thousand years ago. The ancient 
world, especially Greece, was close on the threshold of great dis- 
coveries. 
The steam engine, which is, I think, the most important inven- 
tion in the history of mankind and one of the greatest factors in 
civilisation, was created and operated by Hero, a Greek engineer of 
Alexandria as far hack as 150 B.C. 
This engine, called by Hero the “Aeolipile” was of a primitive 
rotary type, in which the pressure of steam was maintained in the 
boiler, and the steam, escaping under pressure from jets, caused the 
engine to rotate. 
Hero also described his air and water pumps with cylinders 
and pistons, and it was not until the lapse of eighteen centuries 
that t He steam engine with cylinders and pistons was designed by 
Papin and others, and steadily developed into the steam engine of 
to-day. 
The name Electricity is derived from “Elekfcron,” the Greek 
name for Amber— a material which, when rubbed, attracts small 
particles of straw, paper, etc. 
Thales of Militus, 600 B.C., is credited with having pointed out 
this property of Amber, but there does not appear to be any record 
of further knowledge on the subject until the 16th century, when 
Gilbert published a work on Magnetism and Electricity. 
The printing press was known to the Chinese many centuries 
ago, but not until the 16th century was it re-invented in Europe. 
I think we may fairly assume that but for the dark ages 
railways, steamers, electric machinery and appliances might have 
been invented a thousand years instead of about one hundred 
years ago. 
It is hard to realise what our present conditions would be if 
the sciences of astronomy, chemistry, engineering and biology and 
political economy and social conditions had ten centuries ot know- 
ledge and experience behind them. Indeed we have lost a thou- 
sand years of progress. 
When we look back on the ruins and wrecks of the civilisa- 
tions of Babylonia, Egypt, Greece, and Rome, we may well ask 
“Is our own civilisation and science secure from similar annihila- 
tion?” 
During the last hundred years the teaching of science has 
advanced perhaps more than in any other period of history and 
it has become world-wide. The same laws and facts are taught 
in the class rooms and laboratories in every University throughout 
Europe, 
Asia, Africa, America, and Australia. The starry 
heavens, the seas and mountains, the trees and flowers— sublime 
works of nature — are common to all mankind, and the study of 
these forms the language and thoughts of science. 
