Copyright Goodheart-Willcox Co., Inc.
162 Section 1 Preparing to Build
When you swing (rotate) the telescope of the builder’s
level or transit, the graduated circle remains stationary,
but another scale, called the vernier scale, moves. It is
marked off in 15-minute intervals. When laying out or
measuring angles where there are fractions of degrees
involved, you will use this vernier scale.
Figure 8‑19A shows a section of the graduated cir-
cle and the scale. It reads 75°. Notice that the zero
mark on the vernier exactly lines up with the 75° mark.
Now look at Figure 8‑19B. The zero mark has moved
past the mark for 75°, but is not on 76°. You need to
read along the vernier scale until you find a mark that
is closest to being directly over a degree mark on the
circle. That number is 45. The reading is 75°, plus the
number on the vernier, 45 minutes.
Vernier scales will not be the same on all instruments.
Study the operator’s manual for instructions about the
particular model you are using.
8.5.2 Laying Out and Staking a Building
Staking out is done before establishing the grade level.
It begins with locating the lot lines. Corners of the lot
should normally be marked with stakes. Then, take the
following actions:
1. Center and level the instrument (builder’s level
or transit) over the lot corner stake. Measure the
setback called for by local codes. Sight across to
the opposite corner stake.
2. Drive a 2×2 stake at the setback in line with the
lot stakes. Use the transit or builder’s level to
check alignment. The vertical and horizontal
crosshairs should center on the top of the stake.
Drive a nail in the top-center of the stake.
3. Place another stake at the correct setback for one
side of the property line. You are now ready to
stake out the building lines.
P R O C E D U R E
Staking a Building
Staking out building lines requires two people. When a
builder’s level is used, the second person will use a rod
that must be plumbed along the line of sight. Since a
transit can pivot up and down, the second person uses a
stake to locate corners along the building line.
1. Attach a plumb bob to the center screw or hook on
the underside of the instrument. Some instruments
have an optical plumb for zeroing in over a point.
Shift the tripod until the point of the plumb bob
is directly over the point marking the corner of
the building lines. This is at point A on line AB, as
shown in Figure 8‑20.
2. Level the instrument before proceeding further.
Recheck for plumb.
3. From point A (or station A), turn the telescope so the
vertical crosshair is directly in line with the edge of
a stake or rod held at point B. When using a transit,
sight the telescope on the stake.
4. Use a measuring tape along line AB to locate distance
to the corner. Drive a corner stake at this point.
5. Set the horizontal circle on the instrument at zero to
align with the vernier zero and swing the instrument
90° (or any other required angle).
6. Position the rod or stake along line AC so it aligns
with the crosshairs.
7. Locate the other corner along line AC using a
measuring tape.
8. Move the instrument to point C, sight back to point A,
and then turn 90° to locate the line of sight to point D.
9. Measure the distance to point D and place a stake.
10. Use a measuring tape to check the diagonal
distances. If these are equal, the building line
is square. If the resulting figure is a rectangle or
square, you have completed the layout. However,
you may want to move the instrument to point D to
check your work.
80 70
60 30 45 60
15015 4530
60
50
40
30
90
80
70
60
5
0 75°, 45 Minutes
B David White
Figure 8‑19. Reading the horizontal circle of a transit. A—When the zero mark of the vernier is exactly on a degree mark, the
reading is an even degree. In this case, the reading is 75°. B—When the zero mark is between degrees, read across the vernier
to find the minute mark that aligns with a degree mark. This reading is 75°, 45′.
80 70
60 30 45 60
15015 4530
60
50
40
30
90
80
70
60
5
0
Vernier scale
75°
A David White
162 Section 1 Preparing to Build
When you swing (rotate) the telescope of the builder’s
level or transit, the graduated circle remains stationary,
but another scale, called the vernier scale, moves. It is
marked off in 15-minute intervals. When laying out or
measuring angles where there are fractions of degrees
involved, you will use this vernier scale.
Figure 8‑19A shows a section of the graduated cir-
cle and the scale. It reads 75°. Notice that the zero
mark on the vernier exactly lines up with the 75° mark.
Now look at Figure 8‑19B. The zero mark has moved
past the mark for 75°, but is not on 76°. You need to
read along the vernier scale until you find a mark that
is closest to being directly over a degree mark on the
circle. That number is 45. The reading is 75°, plus the
number on the vernier, 45 minutes.
Vernier scales will not be the same on all instruments.
Study the operator’s manual for instructions about the
particular model you are using.
8.5.2 Laying Out and Staking a Building
Staking out is done before establishing the grade level.
It begins with locating the lot lines. Corners of the lot
should normally be marked with stakes. Then, take the
following actions:
1. Center and level the instrument (builder’s level
or transit) over the lot corner stake. Measure the
setback called for by local codes. Sight across to
the opposite corner stake.
2. Drive a 2×2 stake at the setback in line with the
lot stakes. Use the transit or builder’s level to
check alignment. The vertical and horizontal
crosshairs should center on the top of the stake.
Drive a nail in the top-center of the stake.
3. Place another stake at the correct setback for one
side of the property line. You are now ready to
stake out the building lines.
P R O C E D U R E
Staking a Building
Staking out building lines requires two people. When a
builder’s level is used, the second person will use a rod
that must be plumbed along the line of sight. Since a
transit can pivot up and down, the second person uses a
stake to locate corners along the building line.
1. Attach a plumb bob to the center screw or hook on
the underside of the instrument. Some instruments
have an optical plumb for zeroing in over a point.
Shift the tripod until the point of the plumb bob
is directly over the point marking the corner of
the building lines. This is at point A on line AB, as
shown in Figure 8‑20.
2. Level the instrument before proceeding further.
Recheck for plumb.
3. From point A (or station A), turn the telescope so the
vertical crosshair is directly in line with the edge of
a stake or rod held at point B. When using a transit,
sight the telescope on the stake.
4. Use a measuring tape along line AB to locate distance
to the corner. Drive a corner stake at this point.
5. Set the horizontal circle on the instrument at zero to
align with the vernier zero and swing the instrument
90° (or any other required angle).
6. Position the rod or stake along line AC so it aligns
with the crosshairs.
7. Locate the other corner along line AC using a
measuring tape.
8. Move the instrument to point C, sight back to point A,
and then turn 90° to locate the line of sight to point D.
9. Measure the distance to point D and place a stake.
10. Use a measuring tape to check the diagonal
distances. If these are equal, the building line
is square. If the resulting figure is a rectangle or
square, you have completed the layout. However,
you may want to move the instrument to point D to
check your work.
80 70
60 30 45 60
15015 4530
60
50
40
30
90
80
70
60
5
0 75°, 45 Minutes
B David White
Figure 8‑19. Reading the horizontal circle of a transit. A—When the zero mark of the vernier is exactly on a degree mark, the
reading is an even degree. In this case, the reading is 75°. B—When the zero mark is between degrees, read across the vernier
to find the minute mark that aligns with a degree mark. This reading is 75°, 45′.
80 70
60 30 45 60
15015 4530
60
50
40
30
90
80
70
60
5
0
Vernier scale
75°
A David White