102 
THE MEDITERRANEAN NATURALIST 
There are, of course, many intricate details and 
agencies that cannot be discussed in an article of 
limited scope, like the present one. When we come 
to consider the actual structure of known moun- 
tain ranges, it will be the time to inquire whether 
internal stresses by increase of bulk through ex- 
pansion by heat can account for their characteristic 
forms and structure. 
There is, however, another important principle | 
which must not be overlooked. It is this: Every i 
r'se of temperature, however small, goes towards ! 
the lateral pushing up of mountain ridges The j 
rocky material by expansion is actually moved by j 
slow degrees towards the locus of the mountain 
range whereby its bulk grows; subsequent con- 
traction cannot bring it back again any more than 
it can efface the ridging up of sheet lead caused 
by small increases of temperature already refer- 
red to, consequently the effects are cumulative. 
Contraction is the cause of a different set of phe- 
nomena, which will be considered in another ar- 
ticle. One aspect of the question will be readily 
apprehended. It is this: The greatest stresses are 
by this theory the deepest seated, which accords 
with the facts insisted upon at the British Asso- 
ciation discussion, and urged as fatal to the ex- 
istence of a “level-of-no-strain” in the earth, na- 
mely, that the oldest and deepest seated rocks 
generally show the most evidences of pressure. 
Such facts do not disprove the existence of a “level 
-of -no-strain ’ 5 in the earth; they only show that we 
must look to another source than the contraction 
of the earth for the cause of mountain upheaval 
and indicate that other forces come into play which 
obscure, if they do not obliterate, the mathema- 
tically-deduced effects of the contraction of a cool- 
ing globe. 
The theory of which this is but a slight out- 
line I designate “A Theory of the Origin of 
Mountain-Ranges by Sedimentary Landing and 
Cumulative Recurrent Expansion 
(to be continued). 
The Climate of the Maltese Islands. 
“Adieu, ye joys of La Vallette! 
Adieu, sirocco, sun and sweat! 
I’ll not offend with words uncivil 
And wish thee rudely at the Devil; 
But only stare from out my casement, 
And ask, for what is such a place meant?” 
Byron. 
And yet there are few places situated within 
the same parallels, that enjoy so equable a climate 
as do the Maltese Islands. 
The short sojourn made by the ordinary visitor 
is not of sufficient length to allow of a just esti- 
mate of the climate being formed; and, moreover, 
situated as the principal city of Malta is, in the 
most unpicturesque, and uninviting part of the 
island, where there is neither tree nor shrub, hill 
nor valley to relieve the monotony of the long- 
drawn swellings, and uudulatory outlines that 
sweep from the eastern extremity of Malta to the 
foot of the Binjemmas, the tourist has but few 
opportunities of seeing the more fertile districts, 
and so the impressions that his short acquaintance 
with the “Fiordel Monde” make on him, are often 
the reverse of being favourable, and the disappoint- 
ment that is thus engendered finds vent in an 
indiscriminate condemnation of all and everything 
connected with the place, in the course of which 
the climate receives its due share of opprobium. 
That the strictures passed on the climate are 
unjust, may best be proved by a brief consider- 
ation of the principal facts connected with the 
meteorological phenomena of the islands. 
The geographical position of Malta and Oozo, 
serves as a fair index of the nature of the meteo- 
rological conditions, that the physical geographer 
might expect to find. 
Situated in the midst of an extensive land- 
locked sea, the waters of which serve in the sum- 
mer to modify and cool the blasts that sweep over 
from the burning plains of Africa, and in the 
winter to raise the temperature of the icy winds 
that blow from the snow-clad summits of the 
mountains of southern Europe, the Maltese Islands 
may be said to occupy a unique position; for the 
equalizing influences of the surrounding waters 
render them much less subject to variations of 
temperature, aud while they enjoy the mild and 
bracing springs that characterize the areas on 
either side of them, they experience neither the 
extreme heat of the southern summer, nor the 
piercing cold of the northern winter. 
In order that the nature of the differences that 
exist can be the better appreciated, I propose in 
the following brief observations to institute a 
comparison between some of the meteorological 
phenomena of these islands, and similar pheno- 
mena in the south-east of England ; and for this 
purpose, and to avoid entering into wearisome 
statistical details, I shall consider the climate of 
the two areas under the broad headings of the 
distribution of heat during the different months 
and seasons, the variations of air pressure during 
the same periods, the rainfull and its distribution 
during the year, the dryness or moisture of the 
air, and the prevailing winds. 
