s impossible to secure a ridge count. The type lines run parallel
from the left in figures 136 and 137. These tented arches have two of
the loop characteristics, recurve and delta, but lack the third, the
ridge count.

In figure 138, the reader will note the similarity to the figures 136
and 137. The only difference is that in this figure the type lines are
running parallel from the right. It will be noted from these three
patterns that the spaces between the type lines at their divergence
show nothing which could be considered as delta formations except the
looping ridges. Such patterns are classified as tented arches because
the ridge count necessary for a loop is lacking.

[Illustration: 138]

[Illustration: 139]

[Illustration: 140]

[Illustration: 141]

Figure 139 is an example of a tented arch. In this pattern, if the
looping ridge approached the vertical it could possibly be a one-count
loop. Once studied, however, the pattern presents no real difficulty.
There are no ridges intervening between the delta, which is formed by
a bifurcation, and the core. It will be noted that the core, in this
case, is at the center of the recurve, unlike those loops which are
broadside to the delta and in which the core is placed upon the
shoulder. This pattern has a recurve and a separate delta, but it
still lacks the ridge count necessary to make it a loop.

Figures 140 and 141 are examples of tented arches. These two figures
are similar in many ways. Each of these prints has three abrupt ending
ridges but lacks a recurve; however, in figure 141 a delta is present
in addition to the three abrupt ending ridges. This condition does not
exist in figure 140, where the lower ending ridge is the delta.

When interpreting a pattern consisting of two ending ridges and a
delta but lacking a recurve, do not confuse the ridge count of the
tented arch with that of the ridge count for the loop. The ridge count
of the tented arch is merely a convention of fingerprinting, a fiction
designed to facilitate a scientific classification of tented arches,
and has no connection with a loop. To obtain a true ridge count there
must be a looping ridge which is crossed freely by an imaginary line
drawn between the delta and the core. The ridge count referred to as
such in connection with the tented arches possessing ending ridges and
no recurve is obtained by imagining that the ending ridges are joined
by a recurve only for the purpose of locat