e foot rules. They
were then led to observe with care, tables, desks, etc., and to estimate
their length, and were afterward permitted to measure them, and discover
the degree of accuracy in their decisions. After obtaining the opinions
of the children in relation to the length or height of an object, I
would measure it myself in the presence of the class. When the class
became a little experienced, we examined the length, breadth, and height
of rooms, of houses, and of churches; and then the distance of objects
less or more remote, correcting or confirming their estimates by the
application of the rule or measure, which gave a permanent interest to
the exercise. By exercising the class in this manner, not to exceed half
an hour a day, they would, at the end of the first quarter, judge of
each other's height, of the height of persons generally, of the length
of various objects, of the size of buildings, and of the dimensions of
yards, gardens, and fields, with greater accuracy than the average of
adult persons, as was tested by actual measurement in some instances
where there was a disagreement in opinion.

By holding these rules in different positions, the children readily
became familiar with the meaning and practical application of the terms
perpendicular, horizontal, and oblique. They would also tell which term
is applicable to the different parts of the stove-pipe; to the different
parts of the furniture of the school-room; to the floor, sides of the
room, roof, etc.; and to all objects with which they were familiar.

But the reader may inquire, what is the use of the holes and the pins?
By pinning two rules together, one resting upon the other, and then
turning one of them around, the class will readily gain a correct idea
of the use of the term _angle_; also of the terms acute angle, right
angle, and obtuse angle. By pinning three of these rules together at
their ends, the children not only _see_, but can _handle_ the simplest
form of geometrical figures. When this figure is _defined_, they are
enabled permanently to possess themselves of the meaning of the word
_triangle_, by the simultaneous exercise of _three senses_. By combining
rules of the same and different lengths, they become familiar with
equilateral, isosceles, scalene, right, and obtuse angled triangles. By
combining, in this way, such a set of rules as I have described, the
child readily becomes familiar with the names and many of the properties
of