d)
Select pebbles F to I and arrange behind the front row of pebbles,
ensuring that flame paths as indicated below are not interupted.
.
(See fig. 12 below)
Fig. 12
F
e)
Select pebbles (J & N) and position to fill the gaps at each end of the
third row of pebbles, as shown below in Fig. 13
Fig. 13
J
I
H
G
N
15