PHYSICAL CONSERVATION AND RESTORATION. oat 
such historical evidence as still exists, may be expected at no 
distant period to throw much light on this subject. 
Australia and New Zealand are, perhaps, the countries from 
which we have a right to expect the fullest elucidation of these 
difficult and disputable problems. Their colonization did not 
commence until the physical sciences had become matter of 
almost universal attention, and is, indeed, so recent that the 
memory of living men embraces the principal epochs of their 
history; the peculiarities of their fauna, their flora, and their 
geology are such as to have excited for them the liveliest inter- 
est of the votaries of natural science; their mines have given 
their people the necessary wealth for procuring the means of 
instrumental observation, and the leisure required for the pursuit 
of scientific research; and large tracts of virgin forest and 
natural meadow are rapidly passing under the control of civil- 
ized man. Here, then, exist greater facilities and stronger 
motives for the careful study of the topics in question than have 
ever been found combined in any other theatre of European 
colonization. 
In North America, the change from the natural to the arti- 
ficial condition of terrestrial surface began about the period 
when the most important instruments of meteorological obser- 
vation were invented. The first settlers in the territory now 
constituting the United States and the British American proy- 
inces had other things to do than to tabulate barometrical and 
thermometrical readings, but there remain some interesting 
physical records from the early days of the colonies,* and there 
* The Travels of Dr. Dwight, president of Yale College, which embody the 
results of his personal observations, and of his inquiries among the early set- 
tlers, in his vacation excursions in the Northern States of the American 
Union, though presenting few instrumental measurements or tabulated re- 
sults, are of value for the powers of observation they exhibit, and for the 
sound common sense with which many natural phenomena, such for instance 
as the formation of the river meadows, called ‘‘intervales,” in New England, 
ave explained. They present a true and interesting picture of physical condi- 
tions, many of which have long ceased to exist in the theatre of his researches, 
and of which few other records are extant, 
