ISOMETRICAL DRAWING. 
129 
50 feet long and 20 wide, a house 33 feet by 20, 
with some trees, hedges, walls, and tombstones, 
all which are delineated on a scale of 100 feet to* 
1^ inch; and so far as the exact relative size and 
position of these objects on one plane are concern 
ed, no other mode of planning can ever compete 
with this for simplicity, and for the convenience of 
measuring distances in any direction. But if it 
were required to show also the height of the 
church and house, the depth of borings, and the 
strata intersected by them, recourse must be had 
to vertical sections or elevations, and the two 
sides AB and BC can only be shown by two- 
separate drawings as at Fig. 2 and 3. In these, 
the heights, of the church 25 feet, the tower 50 
feet, and the house 20 feet, are distinctly shown - y 
and the depths of the borings, viz. No. 1, 10 
fathoms, of No. 2, 15 fathoms, of No. 3, 14 
fathoms, are also correctly delineated. Hence 
these separate drawings, viz. the ground plan, and 
two sections, afford a correct idea of the three 
several planes represented, but each drawing 
comprehends only the objects which are upon 
that particular plane. The ground plan, Fig. 1, 
gives no idea of the heights or depths ; and the 
vertical sections, Fig. 2 and 3, give no idea of the 
relative area and position of the surface objects. 
Fig. 4 represents an isometrical drawing showing