Fuly 15, 1886] 
NATORE 
251 
motion, these currents cannot be maintained in a radial direction. 
A rotary motion, rapidly augmenting, will take place, producing 
a vortex more powerful than any imagined by Descartes. The 
radial currents of the vaporous column having assumed a spiral 
course, will rapidly acquire a velocity exceed that of a cyclone. 
The practical effect of the powerful movement of the vortex, it 
is reasonable to suppose, will resemble that of a gigantic carving- 
tool whose thorough efficiency in removing irregularities has been 
proved by the exact circular outline presented by thousands of 
lunar formations. The terraces within the “ ring mountains” in- 
dicated on Beer and Madler’s chart, it may be shown, were 
produced by evaporation resulting from low temperature and 
reduced energy after the formation of the main glacier. 
There is another feature in the lunar landscape scarcely less 
remarkable than its circular walls and depressions. In the centre 
of nearly all of the latter one or more conical hills rise, in some 
cases several thousand feet high. Has the rotary motion of the 
boiling vortex any connection with these central cones? A 
brief explanation will show that the connection is quite intimate. 
The under-rated estimate that 10 square feet of surface under 
the action of slow fire is capable of developing one horse- 
power proves the presence of a dynamic energy exceeding 
5,009,090,000 of horse-power at the base of the vaporous 
column resting on the boiling water of a pond as large as that 
of Tycho. No part of this power can be exerted vertically, as 
already explained, on the ground that the weight of the vapour 
restrains such movement. The great velocity of the vortex re- 
sulting from the expenditure of the stated amount of dynamic 
energy will of course produce corresponding centrifugal force ; 
hence a maelstrém will be formed capable of draining the cen- 
tral part of the pond, leaving the same dry, unless the water be 
very deep, in which case the appearance of a dry bottom will 
__ be postponed until a certain quantity of water has been trans- 
_ ferred to the glacier. Tt should be observed that the central part 
© 4 & 
of the bottom, freed from water, will also be freed from the 
surrounding cold by the protection afforded by the vaporous 
mass. The quantity of snow formed above the centre, at great 
altitude, will be small, and of course diverged during the fall. 
_ Evidently the dry ceatral part, prevented, as shown, from cool- 
| ing, will soon acquire a high temperature, admitting the forma- 
tion of a vent for the expulsion of lava, called for as the moon, 
whose entire dry surface is radiating against space, shrinks rapidly 
under the forced refrigeration attending glacier-formation. Lava- 
cones similar to those of terrestrial volcanoes, and central to 
_ the circular walls, may thus be formed, the process being favoured 
by the feebleness of the moon’s attraction. The existence of 
_ warm springs on the protected central plains is very probable ; 
_ hence the formation of cones of ice might take place during the 
last stages of glacier-formation, when those plains no longer 
_ receive adequate protection against cold. 
____ In accordance with the views expressed in the monograph read 
j before the American Academy of Science, continued research has 
_ confirmed my supposition that the water on the moon bears the 
same proportion to its mass as the water of the oceans to the 
terrestrial mass. I have consequently calculated the contents of 
the circular walls of the ‘‘ring mountains” measured and 
_ delineated by Beer and Madler, and find that these walls contain 
630,000 cubic miles. The opposite hemisphere of the moon 
__ being subjected to similar vicissitudes of heat and cold as the one 
_ presented to the earth, the contents of the circular walls not seen 
_ cannot vary very much from those recorded in ‘‘ Der Mond”; 
_ hence the total will amount to 1,260,000 cubic miles. Allowing 
_ for the difference of specific gravity of ice, the statel amount 
_ represents 1,159,090 cubic miles of water. But ‘*Der Mond” 
_ does not record any of the minor circular walls which, as shown 
__ by the large photograph before referred to, cover the entire sur- 
- face of some parts of the moon. On careful comparison it will 
be found that the contents of the omitted circular formations is 
so great that an addition of 50 per cent. to the before-stated 
_ amount is called for. An addition of 25 per cent. for the ice- 
fields, whose extent is indicated by cracks and optical pheno- 
mena, is likewise proper. The sum total of water on the moon, 
therefore, amounts to 2,028,600 cubic miles. 
Adopting [Herschel’s estimate of the moon’s comparative mass, 
_ Viz. 0°011364, and assuming that the oceans of the earth cover 
130,000,009 square miles, it will be seen that the estimated 
‘quantity of water on the moon corresponds with a mean depth 
__ of 7250 feet of the terrestrial oceans.! This depth azrees very 
es 
7 
2028600 X 5280 
~ 130000000 X 0'011364 
rresponding w.th water on the moon, 
s =7250 fect mean depth of ‘terrestrial ocean; 
nearly with the oceanic mean depth established by the soundings 
for the original Atlantic cable, viz. 7500 feet ; but the result of 
the Challenger Expedition points to a much greater depth. This 
circumstance is by no means conclusive against the supposition 
that the satellite and the primary are covered with water in rela- 
tively equal quantities. The correctness of Sir John Herschel’s 
demonstration proving the tendency of the water on the lunar 
surface to flow to the hemisphere furthest from the earth must be 
| disproved before we reject the assumption that the quantity of 
water on the surface of the moon bears the same proportion to 
its mass as the quantity of water on the earth to the terrestrial 
mass. Joun Ericsson 
SCIENTIFIC SERIALS 
Renticonti del Reale [stituto Lombardo, May 27.—Determina- 
tion of the heat of fusion in the alloys oflead, tin, bismuth, and 
zinc, by Prof. D. Mazzotto. By the cooling process usually 
adopted for determining the specific heat of liquids, the author 
finds the point of fusion and the heat of fusion for these various 
chemical alloys as under :— 
Point of fusion Heat of fusion 
Tin and lead ... 181 10°29 
Tin and zinc ... 196 16°20 
Tin and bismuth 38 11065 
Bismuth and lead ... 126 4°744 
Two of these coincide and two others differ little from the composi- 
tion of the chemical alloys as given by Rudberg.—Education 
and crime in Italy, by S. Amato Amati. In order to ascertain the 
influence of public instruction on the criminal classes in the 
Peninsula, the author has compiled a number of comparative 
tables based on official returns ranging from the year 1871 to 
1883 inclusive. For the last three years of this period the 
results are as under :— 
Could read 
Criminals Unlettered areionte Educated 
1831 8693 55Ir 3031 Ist 
1882... = 7099 4139 2671 199 
1883... 6490 3741 2596 153 
According to the three last census returns the total percentage of 
unlettered was as under :— 
Males Females Total 
1861 65°47 81°52 73°50 
1871 60°16 77°18 68°64 
1881 53°89 72°93 63°45 
—Meteorological observations made at the Brera Observatory, 
Milan, during the month of May. 
SOCIETIES AND ACADEMIES 
LONDON 
Royal Society, May 6.—‘ Further Discussion of the Sun- 
spot Spectra Observations made at Kensington.” By J. Norman 
Lockyer. Communicated to the Royal Society by the Solar 
Physics Committee. a : 
I have recently discussed, in a preliminary manner, the lines 
of several of the chemical elements most widened in the 700 
spots observed at Kensington. 
The period of observation commences November 1879, and 
extends to August 1885. It includes, therefore, the sunspot 
curve from a minimum to a maximum and some distance 
beyond. c 
It is perhaps desirable that I should here state the way in 
which the observations have been made. The work, which has 
been chiefly done by Messrs, Lawrance and Greening, simply 
consists of a survey of the two regions F—é and 6—D. t 
The most widened line in each region—not the widest line, 
but the 72st wid-ned, is first noted ; its wave-length being given 
in the observation books from Anzstrém’s map. Next,-the lines 
which most newly approach the first one in widening are re- 
corded, and so on till the positions of six lines have been noted, 
the wave-lengths being given from Angstrém's map, for each 
region. ; i 
It is to be observed that these observations are made without 
any reference whatever to the origin of the lines ; that is to say 
it is no part of the observer's work to see whether there are 
! metallic coincidences or not; this point has only been inquired 
into inthe present reductions, that is, seven months after the 
