JANUARY 29, 1914| 
NATURE 
621 
frequently consulted volumes. The Big Butte is a 
conspicuous rhyolitic hill rising above a somewhat 
dreary country of quartz-monzonite and andesite. The 
bare surface, however, allows the mineral veins to be 
traced over wide areas, and the district is now second 
only to the South African Rand as a producer of 
metals. The main ores are those of copper, contain- 
ing 14 per cent. of silver. The volume includes a 
large number of vein-plans, and illustrations of the 
connection between separation-planes and ore-deposits 
in the crystalline igneous rocks. The ores were accu- 
mulated in these fundamental masses at some epoch 
prior to the eruption of the voleanic rocks at the close 
of the Cretaceous period. The conclusions as to their 
modes of origin may be compared with those of J. D. 
Irving and H. Bancroft for the district of Lake City, 
Colorado (Bulletin 478),° where similar conditions 
occur. . ‘ 
Paper 75 is by F. L. Ransome, on the Breckenridge 
District, Colorado. Here gold is again the attraction, 
and the district has rapidly developed since 1909, when 
new dredges were introduced for dealing with the 
gravels. The glacial deposits show, as is so very 
general in America, two epochs of ice-advance and 
ice-retreat (p. 72). The fissures containing the sul- 
phide ores and the gold from which the placer ores 
are derived were formed by earth-movements in early 
Cainozoic times. 
It is impossible in a brief outline to do justice to 
the large volume (Monograph LII.) on the geology 
of the Lake Superior region, by C. R. van Hise and 
C. K. Leith. Much of the discussion on the pre- 
Cambrian series concerns the Dominion. of Canada 
also, and miners will find a comprehensive account 
(pp. 460-596) of the ores of iron, copper, gold, and 
silver in the district. The ferruginous cherts, with 
hzmatite or limonite, are held to have arisen from 
the oxidation of cherty iron carbonates and of the 
green silicate greenalite, (Fe,Mg)SiO,.nH,O. The 
green oolitic ores with hematite of Dodge County, 
Wisconsin (pp. 567 and 536), which are regarded as 
having been deposited in a granular form in the sea, 
and the greenalite rocks of the Mesabi District (p. 165), 
invite comparison with the ironstones containing green 
oolitic grains in the Silurian rocks of North Wales 
(p. 509), concerning which the last word has by no 
means been said; while the red banded cherts. remind 
us of similar stratified deposits in South Africa. The 
authors believe that the iron, whether haematite or 
magnetite, was largely introduced into the Lake Supe- 
rior sediments from the adjacent basic igneous rocks, 
at a time when the latter were hot and capable of 
sending magmatic waters into the sea in which the 
sediments were accumulating (pp. 516 and 527). 
In Bulletin 503, E. C. Harder indicates the develop- 
ment of the iron and steel industry on the Pacific 
coast of California. : 
Bulletin sos (1911), by A. C. Veatch, is a summary 
of the mining laws of Australia and New Zealand, 
with testimony by practical miners as to their opera- 
tion. The material of the bulletin was brought 
together for a report to Congress, to assist in framing 
regulations for granting leases of public coal-lands in 
the United States. 
The Geological Survey of Alabama, working in 
cooperation with that of the United States, reports 
(Bulletin No. ro) on the Fayette Gas Field in the 
north-west of the State, where gas rises freely from 
small “‘gas-pools" in a coalfield of Upper Carbon- 
iferous age. Further explorations are recommended. 
The development of roads throughout Alabama by 
the use of selected material is discussed by W. F. 
Prouty in Bulletin No. 11, and there seems evidence 
that the lesson taught to Europe by the Romans, and 
NO. 2309, VOL. 92] 
long neglected by their successors, is at last spreading 
in the United States. It will be many years, however, 
before these civilised communities will possess the 
advantages given by French rule to the Berbers of 
North Africa. 
The Wisconsin Geological and Natural History Sur- 
vey issues (1912) a neat volume on the sandstones of 
Lake Superior, by F. T. Thwaites. The Bayfield 
group is the centre of interest, and is placed (p. 104) 
below the Cambrian, representing a sandy terminal 
phase of the Keweenawan sediments, in a region 
where a basin had been established which became 
choked by alluvial fans from the surrounding hills. 
The Survey also issues a large geological wall-map 
of the whole State, with a view to the requirements 
of public education. 
In continuation of its handsome series of cloth- 
bound volumes, the Maryland Geological Survey pub- 
lishes a work by W. B. Clark (State geologist), A. B. 
Bibbins, E. W. Berry, and R. Swann Lull, on the 
Lower Cretaceous deposits of the State. Mr. Berry 
(p. 99) takes the opportunity to summarise, with 
specific lists, the Lower Cretaceous floras of the 
world. As regards British deposits, he points out that 
we are not yet in possession, of all that may be 
expected from the work of Dr. Stopes. Vol. ix. of the 
reports of the Survey treats largely of highway con- 
struction, but includes a history and description of 
the iron industry in the State. Prince George’s County 
has been described in the latest of the interesting 
county monographs, with complete topographical and 
geological maps on the scale of one inch to one mile. 
We can imagine nothing better for the information of 
teachers in the local public schools. 
The Iowa Geological Survey, in a massive volume 
issued at the close of 1912, includes its annual reports 
and papers for 1910 and 1911. More than 1100 pages 
are devoted to a thorough study of the underground 
waters of the State, including (p. 268) several mineral 
springs. 
In The American Journal of Science, vol. xXxxv. 
(1913), p- 1, J. W. Goldthwait, whose Canadian work 
has been already mentioned, describes cirques in New 
England, which, as seems natural, were occupied by 
small glaciers both before and after the great exten- 
sion of continentalice. On p. 139, F. A. Perret carries 
us to ‘The Lava Fountains of Kilauea,’ which may 
now be fairly styled American. The mobility of the 
lava is ascribed (p. 143) to its being highly charged 
with an inflammable gas. The blue, and. therefore 
highly actinic, cloud due to the combustion of this 
eas is here shown in photographs. It is well to learn, 
in view of .the great interest aroused by Brun’s 
researches, that the evolved gases are being carefully 
studied on the spot. The author regards those 
emerging from a lava-surface, that is, from a mass 
subject to oxidation, as quite distinct from the far 
purer gas of a great paroxysmal eruption. We must 
admit, in spite of all the work done on fumeroles, that 
we are still on the verge of this great question. In 
the same volume of the journal, p. 611, Mr. Perret 
directs attention to the evidences of occasional explo- 
sive action during the past history of Kilauea. 
ROMER’S “ADVERSARIA.” 
co TUDES sur les notes astronomigues con- 
tenues dans les Adversaria d’Ole Romer,” 
is the title of a paper by G. van Biesbroek 
and A. Tiberghien, published in the Bulletin of the 
Royal Danish Academy of Sciences (112 pp.). The 
‘“* Adversaria” were published in 1919, and were re- 
viewed in Nature (vol. Ixxxvi., p. 4). The authors of 
the present paper give a detailed analysis of most of 
