Part 12 (2/2)

[Ill.u.s.tration: 332]

[Ill.u.s.tration: 333]

[Ill.u.s.tration: 334]

Figure 333 is a plain arch. The rising ridge at the center is curved at the top forming no angle, and does not const.i.tute an upthrust because it is not an ending ridge.

Figure 334 is a whorl of the double loop type. Two loops and two deltas are present. It is unusual because the loops are juxtaposed instead of one flowing over the other, and one delta is almost directly over the other. The tracing is a meeting tracing.

Figure 335 is a tented arch. Although there is a looping ridge, no ridge count can be obtained. The core is placed upon the end of the ridge ab.u.t.ting upon the inside of the loop, and so the imaginary line crosses no looping ridge, which is necessary.

Figure 336 is a plain arch. The ending ridge at the center cannot be considered an upthrust because it does not deviate from the general direction of flow of the ridges on either side. No angle is present as the ending ridge does not abut upon the curving ridge which envelopes it.

[Ill.u.s.tration: 335]

[Ill.u.s.tration: 336]

[Ill.u.s.tration: 337]

[Ill.u.s.tration: 338]

[Ill.u.s.tration: 339]

Figure 337 is a plain arch because the dot cannot be considered a delta as it is not as thick and heavy as the surrounding ridges.

Figure 338 is a tented arch consisting of two ending ridges and a delta. The short ending ridge is considered a ridge because it is slightly elongated and not a mere dot.

In figure 339, the only question involved is where to stop tracing.

The rule is: _when tracing on a ridge with an upward trend, stop at the point on the upward trend which is nearest to the right delta_. X is the point in this pattern.

In figure 340, the question involved is also one of tracing. In this pattern, the tracing is not on a ridge with an upward trend. The tracing, therefore, is continued until a point nearest to the right delta, or the right delta itself, is reached. This tracing is a meeting tracing.

[Ill.u.s.tration: 340]

There are a few constantly recurring patterns which, though not questionable or doubtful as they appear, present a peculiarly difficult problem in cla.s.sifying. The patterns referred to are usually double loops, though accidental whorls and loops sometimes present the same problems. The difficulty arises when a loop is so elongated that the recurve does not appear until near the edge of a fully rolled impression or an impression that is rolled unusually far, as in figures 341 to 344.

[Ill.u.s.tration: 341]

[Ill.u.s.tration: 342]

[Ill.u.s.tration: 343]

[Ill.u.s.tration: 344]

Figure 341, if cla.s.sified as it appears, would be an accidental whorl.

Figures 342 and 343 would be double loops, and ill.u.s.tration 344, a loop. It will be observed that these prints are rolled more fully than normal. If, however, the next time the prints are taken, they are not rolled quite so far, the patterns would require a very different cla.s.sification, and would show no indication of any need for referencing to their true cla.s.sification. The result would be a failure to establish an identification with the original prints. The only way in which such an error may be avoided is to cla.s.sify such impressions as they would appear if not so fully rolled, and to conduct a reference search in the cla.s.sification which would be given to the prints when rolled to the fullest extent. Applying this rule, ill.u.s.tration 341 is a tented arch, referenced to a whorl. Figures 342 and 343 are loops, referenced to whorls. Figure 344 is a plain arch, referenced to a loop.

<script>