252 Tin American Geologist. October, 189* 
Undue stress seems to be laid upon the idea that none of the banding 
of the taconyte is due to sedimentation. It is admitted by the author 
thai the rocks were water-deposited — chemical and mechanical— and ii 
would be extremely surprising if all the banding now so beautifully dis- 
played in the ore and rock alike were dm- to secondary segregation 
and none of it to the original separation by specific gravity or the con- 
i ingencies 6f sedimental ion. 
The specimens examined b\ the author exhibited a smaller percent- 
age of fragmental material than would be expected from a macroscopic 
examination. Indeed, it is difficult to conceive thai the taconyte with 
a thickness of 800 feel can be so completely due to chemical deposition 
as our author would have us believe. 
The ore deposits are believed to owe their existence to chemical solu- 
tions which percolated from the surface downward. The rules deduced 
are that in regions of comparatively free oxidation chalybeate waters 
deposit iron and remove silica; while in regions of scan 1 oxidation silica 
is deposited and iron is carried away in solution. The principal solvents 
are believed to have been oxygen and carbonic acid, with sulphuric acid 
and alkalies as secondary reagents. 
Plates X. XI and XII are double-page maps, showing the geology and 
topography of the central portion of the Mesabi. The area occupied by 
the various rock formations and the location of the ore bodies already 
found are shown quite accurately. These maps furnish the best guides 
for future explorations that can be found, hut the report itself is too 
technical to he of use«to the ordinary prospector. 
As a geological study of the range, this report is of the highest value 
and reflects great credit upon its author. u. v. w. 
Tin nickel ore* of Sudbury, Canada. By John I). Frossard. pp. til. 
Geo. Philip and Son. Loudon. 1893. Chiefly a compilation from vari 
ous articles on the subject withoul discrimination as to t heir value and 
accuracy, l his little book presents little new information. Its chief 
merit lies first in its practical data referring to the average cost of pro- 
duction and quality of the ore at Sudbury, ami second, in the fact that 
it is a sort of a little monograph on nickel ores in general. It is a so 
useful in giving references to the literature, from which more detailed 
and exact information may be gained. it. v. w. 
Miuiiii/ Royalties, tlteir practical operation and <ffi<-t. By ('has. a. 
James, pp.277, Longmans, Green A: Co., London and New York. 1893. 
As stated in the preface, this essay is based wholly on the various vol- 
umes of evidence published by the Royal Commission on Mining Royal- 
ties of Greal Britain; and the royalties referred to are chiefly those paid 
to the' owners of coal mines. The relation of the fee-owiier to the lessee, 
that of royalties to strikes and wages, and their effect on competition 
with oi her count ries, together with mam kindred subjects, are discussed 
from the English standpoint. Although not directly appertaining to 
this country, the volume is interesting to the student of labor questions 
so far as they affect the miuer, and gives a concise view of how such 
