PREFACE. 



THERE are few persons, no matter what their calling or 

 their education, who do not occasionally find themselves at 

 a loss for information of the commonest kind, on any of the 

 subjects pertaining to the practical arts of daily life knowl- 

 edge which was, perhaps, familiar to them in their school- 

 boy days, but which has been forgotten or become obscured 

 through the lapse of years. For example, how few persons 

 can tell, without consulting books, the cubic inches contained 

 in a bushel, the square yards in an acre, or how to measure 

 the contents of a corn crib, or gauge a cistern. Nor is the 

 inability to do so any reflection upon either their native 

 capacity or their education. It is simply impossible to carry 

 all these things in the memory so as to apply them when 

 occasion requires. Hence the necessity for " Hand-Books," 

 " Mechanics' Assistants," " Pocket Companions," &c. 



Besides the labor involved in the almost daily necessity of 

 calculating arithmetical, mensural, and other results, and the 

 constant liability to error to which even the competent 

 scholar is subject, the time required in the process, in this 

 age, when time has emphatically acquired a money value, is 

 no inconsiderable desideratum. Hence the necessity for 

 " Keady Keckoners," " Pocket Accountants," " Calculators' 

 Assistants," &c. 



195064 



