SCIENTIFIC SUMMARY. 
197 
the large proportion of soda, and the fact of mica not being present. That 
it is not dust derived from the basalt area of Greenland is indicated by the 
subordinate position iron-oxide occupies among the constituents, as well as 
by the large proportion of silicic acid. We have, then, to fall back on the 
assumption that it is either of volcanic or cosmical origin ! . . . Whenceso- 
ever it comes, it contains one constituent of cosmical origin. Dr. Nordensk- 
jold, extracted, by means of the magnet, from a large quantity of material 
sufficient particles to determine their metallic nature and composition. 
These grains separate copper from a solution of tbe sulphate, and exhibit 
conclusive evidence of the existence of cobalt, copper,” and nickel (less 
certainly). 
From evidence of this kind Mr. Banyard infers that meteoric matter is 
continually falling in quantities which, in the lapse of ages, must accumu- 
late so as materially to contribute to the matter of the earth’s crust. He 
speaks of this theory, by the way. as one which has been advocated, for some 
time past, by Mr. Proctor. But this is not strictly correct. Mr. Proctor has 
advocated the theory that in remote past ages the earth has thus received 
material increments of mass, but not that meteors are now falling in such 
sort as to increase the earth’s mass, even during many hundreds of thousands of 
years, in any appreciable degree. The total number of meteoric bodies fall- 
ing annually on the earth’s mass, from the largest aerolites down to the smallest 
shooting-star which an ordinary telescope would show (if the body chanced 
to pass across its field of view), has been estimated by Professor Newton, of 
Yale College, at 400,000,000. This only allows an average of two meteors 
per annum for each square mile of the earth’s surface, or roughly about one 
meteor per square yard, in 1,500,000 years. As the average weight of meteors 
is probably to be measured rather by grains than by ounces, we cannot con- 
sider that the addition of one meteor per square yard would involve a very 
noteworthy increase of the earth’s mass 5 and 1,500,000 years must be re- 
garded as fairly equivalent to the time indicated by the rather vague expres- 
sion, u the lapse of ages.” In past times, however, when as yet the great 
bulk of the meteoric matter was still travelling freely around the sun, the 
rate of ingathering must have been far more rapid. 
The Lunar Crater Hyginus . — Lord Lindsay and Dr. Copeland have made 
some interesting and instructive observations on the varying appearance of 
the region near Hyginus, confirming, as they point out, the well-known fact 
that this region “ is full of complicated shallow irregularities and strongly- 
marked differences of tone, which tend together to produce great apparent 
changes of surface configuration, with change of illumination ; and, further, 
to show that there exist striking features in the immediate neighbourhood 
which have hitherto escaped clear detection, but of which some traces may 
be found in the comparatively old map of Lohrmann.” Their statements 
would hardly be intelligible, even to lunar students, without the drawings 
which accompany their paper. Let it suffice to observe, that they fully 
make out their case ; and though their observations have no direct bearing 
on Dr. Klein’s supposed recognition of a new crater in this region, yet 
indirectly they tend to increase the doubt with which the more cautious 
astronomers had received the announcement of the reported change. The 
facts collected also show, as Lord Lindsay and Dr. Copeland say, 11 with 
