March 30, 1871 | 
NATURE 
427 

in some phenomena than in others, and more evident at some 
moments than at others. The questions of the origin, the 
existence, and the value of species in such a system are easily 
appreciated, D. SHARP 
Thornhill, Feb. 23 
The Preponderance of West Winds 
In NATURE of the 16th inst. you appear to contest Mr. 
Laughton’s statement that west winds preponderate over east on 
the entire globe. Ibelieve that Mr. Laughton is right as to the 
fact. We have no reason to think that the earth’s atmosphere is 
acted on from without by any force except the sun’s heat ; if this 
is the case, the winds can have no effect whatever in either 
accelerating or retarding the earth’s rotation ; and, conseqently, 
the east and west winds must exactly balance each other’s effect, 
for if either were unbalanced it would have an effect, however 
small, on the earth’s rotation. But ‘‘an east wind near the 
equator has more effect in retarding the rotation of the earth, 
than a west wind of equal extent and force at a higher latitude 
in accelerating it, just as a weight at the end of the long arm of 
a lever outweighs an equal weight at the end of the short arm. 
It is for this reason that the west winds, which are mostly in the 
higher latitudes, are of greater force, and probably cover a greater 
area than the east winds, which, under the name of trade winds, 
predominate near the equator.” 
This quotation is from a letter of mine published in NATURE 
of 16th Feb. 
In the same number of NATuRE there is a letter from Mr. 
Laughton, maintaining that rain may be caused by fires or ex- 
plosions. ‘This is confirmed by a fact mentioned by Humboldt 
in his Cosmos, that he once saw an eruption of the volcano of 
Cotapaxi in the Andes, during which the cone became red hot, 
and rain fell at an unusual time of the year. 
In the same number is a most interesting account of the 
Winter Meteorological Observatory on Mount Washington in 
New England. Mount Washington must be much more isolated 
than mountains 10,000 feet high generally are; and I hope the 
opportunity may not be lost of making comparative barometric 
observations, extending over a considerable time, at the summit 
and the base. In NATURE of 19th January, you published a 
letter of mine on the importance of such a comparative series. 
OSEPH JOHN MuRPHY 
Old Forge, Dunmurry, Co, Antrim, March 18 
Morell’s Geometry 
Ir was with no small surprise that I found myself accused 
by Mr. J. R. Morell, more than once in last week’s NATURE, of 
having overlooked the fact ‘‘that all the proofs in the work 
(‘Essentials of Geometry’) are taken from French and German 
sources.” Nothing to my mind could be more obvious ‘than 
that throughout my review in NATURE for Feb. 23, I was 
criticising the performance of a compiler. In one instance, 
indeed—Mr. Morell has surely not already forgotten it—I took 
the trouble to show ow Amiot’s demonstration of the funda- 
mental properties of parallels had been mutilated by him. I 
must protest, too, against his claim to freedom from censure on 
the ground that he has merely copied passages from the works of 
our highest authorities ; for it is about as reasonable asa claim to 
sanctity would be on the part of one who habitually, it is said, 
quotes Scripture for his own purposes. 
Utterly ignoring the italics which I introduced, tosave com- 
ment, into his definition of a plane angle, Mr. Morell quotes the 
Greek of Euclid and the English of Thomson, in justification, 
apparently, of the aptness of the introduction of the notion of 
revolution, which no one contested. He compels me, therefore, 
to draw his serious attention to the fact that neither of these 
geometers, nor any other to my knowledge, ever confused mankind 
as he has done by speaking of the ‘‘inclination of two straight 
lines ¢o a common point.” 
Mr. Morell has, lastly, the audacity to defend his pretended 
demonstration, on p. 44, of the theorem that two triangles are 
equal in every respect when the sides of one are respectively equal 
to the sides of the other, by stating, fst, that it “is based on the 
previous pages (42 and 43), overlooked by the Reviewer ;” and, 
secondly, that it ‘agrees almost word for word with Legendre.” 
The first of these statements is absolutely incorrect; on pages 42 
and 43, there is not a word upon which the demonstration 
in question cou/d be based. With respect to the second state- 




ment, I admit that Mr. Morell’s demonstration substantially 
differs from Legendre’s, as given by Blanchet, in Prop. xi. Bk. 1, 
only by the omission of four words ; and to show, by a striking 
example, what mischief scissors can do in Mr. Morell’s hands, I 
will supply the four missing words, between brackets, in the fol- 
lowing reproduction of his demonstration :— 
“Let ABC, DEF, be two triangles, having AB = DE, 
AC = DF, BC = EF, then angle A = D;; for if they were 
unequal, sides BC and EF would be unequal [by the previous 
proposition]. Therefore A =D.” 
The fact that Legrendre’s most essential previous proposition 
is nowhere to be found in Morell’s ‘‘ Essentials of Geometry,” 
sufficiently accounts for the omission of the four words above 
inserted. Mr. Morell, however, has yet to realise the fact that 
these omissions of his have converted a genuine demonstration 
into a mere assertion, or rather into a flagrant ‘‘ violation of the 
most obvious of all logical rules.” 7 
Mr, Morell threatens, if space be given him, to show, on his 
“own authority,” that he has “good arguments for what has 
been advanced.” Before he does so let me remind him that 
logical demonstration, like the multiplication table, is more a 
subject for direct apprehension than for argument. 
THE REVIEWER 
A Meteorological Question 
WHILE glancing the other day over the article ‘‘ Meteorology,” 
in the Supplement to the 4th, 5th, and 6th Editions of the Zvcy- 
clopedia Britannica, I was surprised to find under the marginal 
heading, ‘‘ Hauhber’s Experiment,” the following :— ‘‘ It is con- 
ceived that a current of air in sweeping over the surface of the 
earth, must cease to exert any vertical pressure. But this assump- 
tion can hardly be reconciled with any strict principles in science, 
for the particles of air will not for a moment cease to gravitate, 
nor will any horizontal motion of them produce the slightest de- 
rangement in a perpendicular direction.” Is not this a great 
mistake ? QUARE 


A SUGGESTED NEW DIVISION OF ‘THE 
EARTH INTO ZOOLOGICAL REGIONS 
ee seems now to be generally agreed among zoologists 
who are specially conversant with the fauna of India, 
that “ the Indian Region” of Dr. Sclater and others can 
no longer be regarded as a genuine or natural zoological 
division of the globe, and that India properly so called 
(from the Himdlya to the sea), is rather a border terri- 
tory where different zoological regions meet and are 
variously interposed, at the same time blending, as a 
matter of course, to some extent.* 
This is a subject which has long occupied my thoughts, 
and I am gradually arriving at the opinion that the 
present dry land upon our planet may be most naturally 
divided into seven zoological regions, which again are 
divisible into sub-regions, and these into provinces and 
sub-provinces. 
I. The Boreal Region, whichis divisable into: 1. Arctic 
Sub-region, within the confines of the Arctic Circle, 
but also inclusive of the whole of Greenland, and of 
Foxland (west of Davis Strait and north of Hudson Strait). 
2. Neo-septentrional Sub-region— North America. 3. Neo- 
meridional Sub-region—Central America with the Antilles. 
4. Andisian Sub-region—the chain of the Andes with Chili, 
Patagonia, and the Fuegian and Falkland Archipelagos. 
5. Palzo-septentrional Sub-region—Europe and Asia 
south of the Arctic Circle, and north of the Pyrenees, Alps, 
Taurus, Elburz (south of the Caspian Sea), Hindu Kosh, 
and Western Himdlya, extending from the British Islands 
to Northern Japan? 6. Palzeo-meridional Sub-region—the 
countries adjacent to the Mediterranean, as Africa north 
of the Atlas (with Madeira, the Canaries, and the Azores), 
Spain, Italy, Dalmatia and Illyria, Greece, the islands of 
the Mediterranean and the Levant, Turkey, Asia Minor, 
* Vide Mr. W. T. Blanford in the “ Proceedings of the Asiatic Society ” 
for September 1867, p. 145 ‘‘ The fauna of India at the present day is 
a remarkable mixture of African and Malay forms. The idea, so com- 
monly expressed in European books, of India belonging to the same geologi- 
cal [qu. zoological ?] province as the Malay Peninsula and Southern China, 
is quite erroneous.” Vide also the same “ Proceedings” for January 1868 
p. 18, January 1869, p. 40, and July 1870, p. 238. 
