174 
POPULAR SCIENCE REVIEW. 
THE POLAR WORLD.* 
r E researches of Professor Heer, and of Mr. Whymper and others, have 
lent a new interest to the polar world, and have given us a new in- 
centive to arctic exploration. Hitherto the only object we could suggest 
as justifying polar expeditions, was the trivial one of the possible discovery 
of a useless north-west passage, or the very questionable one of the dis- 
covery of an open polar sea. But we know now, thanks to the labours 
of these savants, that the polar regions must at one time have enjoyed a 
climate as different from that they now experience as ours is from that of 
Northern Africa. Indeed there can now be no longer a doubt, that at one 
period of the earth’s history, the climate of Greenland was even more than 
temperate, and the country possessed a luxuriance of vegetation such as 
could never have been dreamt of but for the discoveries of Heer and his 
colleagues. These discoveries relate to the fossil flora of Greenland, and 
they show us that at a time remote from the present, the polar regions of 
the globe must have had climatal conditions as different as possible from 
those which now prevail. Anyone, therefore, who would select this aspect 
of the polar world, and would give us a good work upon the prehistoric 
polar world, would not only do a service to science, in extending a know- 
ledge of its truths, but would do much to encourage arctic exploration. 
Here is a whole field for study and investigation : will no one take it up ? 
Ostensibly Dr. liar twig has taken it up, but only ostensibly. His book, 
full of interesting details as it is, can hardly lay claim to being considered 
scientific, since the question of most scientific interest in connection with 
the subject is left, we may say, altogether unnoticed. It is true that he 
mentions the fact of a former temperate climate, and corresponding vegeta- 
tion. But his observations on these do not extend beyond a page and a half, 
and tliey close with the most absurd blunder in reference to Oswald Heer’s 
explanation of the cause of the alteration of climate. Indeed the concluding- 
passage is a guarantee of Dr. Hartwig’s unfitness for the task he took in 
hand. He makes Heer say that as the solar system is moving through space, 
and as the fixed stars are blazing suns, it must sometimes be placed in a 
thicker clu.ster of fixed stars than usual, hence the earth must get warmer. 
The warm period of tlie poles corresponded to a time when the solar system 
was thickly surrounded by stars. Since then we have passed into a less 
populous sidereal region,” and hence the change. This is science with a 
vengeance. The popular, or non-scientific parts of the book contain in- 
structive sketches of tlie inhabitants of the European, American, and Asiatic 
Polar districts, and many plea.sant anecdotes clipped from the books of arctic 
explorers. The illustrations are numerous and pretty, but we cannot com- 
mend the work as an accurate one. 
• “ The Polar World : a popular description of Man and Nature in the 
Arctic and AnLirctic Kegions of the Globe.” By Dr. C. Hartwig. London : 
Longmans, 18Gfi. 
