The student can test these forms, and many others that he will see advertised from time to time, by the list of characteristics given above, and can thus form an opinion as to which is best suited for a particular purpose.

FIG, 375.Rendle's Acme"System for squares up to 4ft. in length.

FIG. 376.

FIG. 377.

FIG. 378.

FIG. 379.

FIG. 330.

FIG. 381.

FIG. 382.