378 
NAT ORE 
[JUNE Ir, 1914 
on their high lands than is New Zealand. The 
lofty mountain ranges which traverse both islands, 
and the excessively broken nature of the land over 
large areas, together with an average high rain- 
fall, lead to the presence of innumerable streams, 
and offer ideal conditions for denudation; hence 
the mountains would, if not forest clad, be a 
constant source of danger to the farm lands on 
which the prosperity of the country so largely 
depends. The original covering of forest, which 
—except where soil or climatic conditions were 
adverse—occupied the whole land, and extended 
to a height of between 3000 and 4500 ft., has now 
been enormously reduced, and there has been 
nuch unnecessary destruction extending to the 
steep slopes of hills, and even to the upper alti- 
tudinal limits of the forest; hence the head- 
waters of many streams are no longer provided 
with tree cover, and the general watersheds of 
the larger rivers have lost their original efficient 
protection. The commission strongly recommend, 
therefore, that these mountain forests should be 
strictly preserved against further interference, 
and that every factor which is destructive to the 
forest undergrowth should be rigorously re- 
pressed—this will entail the restriction of deer 
and other destructive animals to limited enclo- 
sures. 
The importance of scenic reserves, which in- 
cludes several distinct classes of reserve, is fully 
realised by the enlightened Government of the 
Dominion, which is annually adding large areas 
to its already long list of such reserves, and is 
in this respect setting a splendid example to older 
countries. In this connection it may be noted 
that of the seventeen hundred species of trees, 
shrubs, herbs, ferns, and fern allies included in 
the New Zealand flora, more than three-fourths 
are found nowhere else in the world, and that this 
vegetation is, except where disturbed by human 
occupation, of a truly primitive type. In 1903 
Sir Joseph Ward, then Minister in charge of the 
Tourist Department, introduced the Scenery Pre- 
servation Act, which provided for a Royal Com- 
mission to report upon all areas possessing scenic 
or historic interest, or on which there were 
thermal springs, and submit recommendations for 
the acquisition of such as seemed desirable, 
whether Crown, freehold, or native. After this 
commission had worked for two years, it was 
terminated by an amending Act substituting a 
small permanent advisory board of Government 
officials, the Scenery Preservation Board, which 
investigates and reports from time to time on all 
areas worthy of inspection, and by a further Act 
passed in 1910 the whole of the reserves were 
made sanctuaries for the flora and fauna, so that 
no firearm may be discharged on a scenic reserve, 
nor may any bird or game be killed thereon. The 
reserves now set aside for scenic purposes number 
518, and there are also five national parks consist- 
ing for the greater part of extremely steep land, 
much of which is at a high altitude and more or 
less barren, while three islands have been set 
apart for the protection of New Zealand birds. 
NO. 2328, Vol, 92] 
The Forestry Commission recommend the consti- 
tution of a further series of scenic reserves. 
The report for 1912 of the Scenery Preservation 
Board shows that during the year ended March 
31,5, 1912, there were acquired no fewer than 
ninety-six additional reserves, with an aggregate 
area of 94,000 acres, at a total cost to the 
Government of less than 6o0o0ol., the latter figure 
including as the two heaviest items the expendi- 
ture involved in survey and the compensation paid 
for private and native lands acquired. Be tGe 
WEE. PRINCIPLE -O}ayhaie i iave 
Lid 
ERHAPS the most comprehensive generalisa- 
tion in physical science since Newton’s 
enunciation of the law of gravitation is the con- 
ception of an all-pervading ether, the medium of 
transmission of light and of electrical and mag- 
netic disturbances. From the time when Maxwell 
adopted this conception from Faraday and es- 
tablished the identity of light and electric waves, 
the ‘‘ether”’ has become a fundamental element 
of our thought about the physical world. 
But it has been a standing puzzle for many 
years to find out whether the ether is pushed 
and carried along by the earth as it moves or 
whether it is of such a nature that it can pass 
through solid matter so that we may think of it 
as undisturbed by the motion of bodies through it. 
Without going over the history of the controversy 
it may be stated that by the beginning of this 
century it had been almost universally accepted 
that the simplest way to think of the ether was 
to suppose it to be stagnant and immovable. 
Thus there seemed a possible solution to an older 
puzzle, that of the failure of mechanics to specify 
a unique and universal frame of reference for the 
motion of bodies. The ether promised to supply 
one. But, unfortunately, when experiments were 
devised to determine the velocity of the earth 
relative to the ether, they one and all failed. Thus 
came into being the principle of relativity, which 
is simply the hypothesis that we never shall know 
or be able to define what is the exact velocity of 
the earth or any other body relative to the aether. 
Of course, this must not be taken as a dogmatic 
assertion or a philcsophic doctrine, but as a 
working hypothesis, the consequences of which 
are to be examined and verified at every possible 
point by comparison with experiment. But the 
boldness of the hypothesis requires a little justi- 
fication. It arose, as a matter of fact, directly 
out of the theory built. up by Lorentz and 
Larmor on the basis of a stagnant ether for the 
purpose of explaining the failure of the experi- 
ments that have been referred to. This theory 
was so comprehensive that it distinctly predicted 
the failure of ali conceivable experiments designed 
for the purpose of identifying the ether as a frame 
relative to which the velocities of bodies might be 
measured; just as the comprehensive dynamical 
theory of Newton, though at the outset it postu- 
lates a standard of absolute position, involves the 
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