h = 1.732l = (7/4)l = (7/4)r;
v = 1.225l = (5/4)l = (5/4)r.

For six-line craters,

h = 4.358l = (35/8)l = (3/2)r;
v = 1.378l = (11/8)l = (½)r.

11. The English authorities adopt the value of 7/4l´ for the horizontal and l´ √(2) = 1.41421 l´ = (7/5)l´ for the vertical radius of rupture of all classes of mines. In which l´ = L. L. R. of an equivalent common mine = l + (7/8)(r-l), etc.

Some later experiments at Chatham have given

v = (5/3)l for a 4-lined crater;
v = 2l for a 5-lined crater;

and