204 JOURNAL OF THE PLYMOUTH INSTITUTION. 
of the world to breathe. Hence the enormous deposits of carbon, 
and the formation of the coal measures. 
But more of the world was sea than land, and this had to be 
compensated for. The carbonate-of-lime burdened sea gave up its 
carbon, the air becoming clearer, and limestone rocks, principally 
through the action of low forms of animal life, are formed coeval 
with the Coal. | 
Amongst the last great discoveries the Spectroscope chimes in. 
Frauenhofer finds his lines, and Angstrom reduces them to order. 
Oh, if poor Galileo could have heard the tale (I must believe he 
has), that it is proved to the satisfaction of the obtusest idiot that 
by the revelation of that wonderful set of prisms the chances are 
sixty-seven billions to one that there is iron in the Sun, a body 
ninety-one millions and odd miles away ! 
On this also hangs part, great part, of our knowledge of the 
rate at which stars move about. The so-called fixed stars are no 
more fixed than we are. Sirius, our nearest friend, is parting 
company at the rate of twenty-seven miles per minute, and yet 
strangely we do not notice it. This has been determined by the law 
laid down by Huggins of the variation of the F line of Hydrogen 
in the gas streams of the sun, the rate being eight geographical 
miles per second. It was he and Zéndorf that first considered the 
spectrum of the corona during eclipses, and first detected and 
observed the great gas streams of incandescent hydrogen. This 
was soon applied to other bodies, especially the nebula of Orion. 
The discrimination between the continuous and the discontinuous 
spectra of nebulz, as regards their constitution, laid down the first 
great laws and thoughts of the primary nebulous constitution of 
all planetary systems. ) 
Geologic thought occupied men’s minds. They began to think 
about and systematize the various strata of the earth. 
They find that stones are carried about by glacial force; that 
sea-shells are found on lofty mountains, because the mountains have 
risen out of the sea. They make blunders, acknowledge them, 
and rectify them, and find that for Nature’s operations even our 
little world wants almost infinity of time. 
Geologic thought has done one thing that even. our fathers 
would have derided. The Patristic chronology laid the date of 
the appearance of man on the earth at six thousand years ago. 
But man has outlived the great European Glacial period. His 
