2 J3 
Notices of Books. 
[April, 
mental calculation. He points out' that “ the mind, after finding 
the product by mental multiplication, which finishes the work in 
a system of integers, has to go in quest of the decimal points of 
the multipliers, reckon their conjoint value, and bring the con- 
joint decimal point down to the product, fix it correCtly there 
between some two figures, and pronounce the money value of 
the product after this mental balancing.” To do all this rapidly 
and correCtly “ in the head ” requires a grasp of figures of which 
few minds are capable. 
The French system is not, strictly speaking, “ decimal in 
money it is centesimal, and in weights and measures millesimal. 
This serious difficulty Mr. Gregory proposes to avoid by the in- 
troduction of a metric ounce and pound, pint and gallon, and 
thus overcome the serious objection to the use of a decimal 
system. 
We strongly recommend this work to our readers, who will 
find it much more interesting than the title might perhaps lead 
them to expeCt. 
The High Antiquity of Iron and Steel. By St. John V. Day, 
Ass. Inst. C.E., F.R.S.E. London : W. LI. Guest. 
The subjeCt of this pamphlet and the results at which the author 
arrives may be understood from the following paragraph : — 
“There is no escape from the conclusion that in all the earliest 
peopled countries — whether peopled by Semitic, Hamitic, Aryan, 
or Allophyllian races — there is most certain proof that in the 
remotest ages which we can ascertain anything about the inhabi- 
tants were familiar with the use and manufacture of iron and 
steel ; that in those countries there is not a tissue of evidence in 
favour of a bone or stone age, still less of a bronze and then of 
an iron age succeeding ; that from the evidence adduced, and 
which indeed is being continually supplemented, it is evident 
the stone, bronze, and iron theory must be consigned to the 
limbo of false ideas and exploded notions.” Do the author’s 
researches do anything more than push back the period of stone 
implements, which, after all, are realities ? 
List of Elevations , principally in that portion of the United 
States West of the Mississippi River. By Henry Gannett. 
Washington : Government Printing Office. 
This pamphlet gives the altitudes of a list of towns, mountains, 
passes, and table-lands in the western portion of the American 
Union, as also those of a few in foreign countries. We notice 
