Transcriber's notes

Only obvious printer's errors have been corrected (e.g.: 3 s instead of 2, etc.). The author's spelling has been maintained and inconsistencies have not been standardised.

The advertisement pages have been move from the front to the end of the book.

Other corrections made:

—Page x: "the wealth of rations" has been replaced by "the wealth of nations".

—Page 17: "Pressure of Rarified Air." has been replaced by "Pressure of Rarefied Air."

—Page 98: "This beautiful contrivance, which is incontestibly" has been replaced by "This beautiful contrivance, which is incontestably".

—Page 100: "the working beam no longer used" has been replaced by "the working beam is no longer used".

—Page 223: "is attended with peliar difficulty" has been replaced by "is attended with peculiar difficulty".

—Page 271: "The projecter is now employed in" has been replaced by "The projector is now employed in".