PREFACE

TO THE FOREIGN AND DOMESTIC COMMERCIAL

CALCULATOR.

This work is composed of the first four sections of the author's

"COMPREHENSIVE MATHEMATICS." It was thought advisable

to publish this portion of that work in a separate form on account

of price; more especially as it contains all of a commercial nature

treated of in that work. Indeed, the contents of that work were

arranged expressly to this end. The Table of Contents in both

works is the same. The work being stereotyped, this could not well

be avoided. The Table of Contents, therefore, in either work, is

that of the "COMPREHENSIVE MATHEMATICS," and the first

four sections thereof; that is, Section I., Section II., Section III.,

and Section A., is that of the "Foreign and Domestic Commer-
cial Calculator."

PREFACE

TO THE TIN-PLATE AND SHEET-IRON WORKERS' MONITOR.

This work is composed of Section VI. of the author's "COM-

PREHENSIVE MATHEMATICS," with portions of other sections of

that work. It embraces all that is contained in the last-mentioned

work of special interest to the Tinsmith, as such. It may be re-

lied on for accuracy in all particulars, and is believed to be the

first and only reliable work of the kind ever published. It is pub-

lished in separate form on account of price, and with the view of

affording apprentices and students every possible facility of obtain-

ing it. It contains over 100 pages, nearly 50 diagrams, and step-

by-step directions for constructing, mechanically, not less than 30

unlike and different patterns, embracing all of the more difficult

and complicated in use, and several of new and beautiful designs.

53 To find the Specific Gravity of a

Body heavier than Water