The Tented Arch



In the tented arch, most of the ridges enter upon one side of the

impression and flow or tend to flow out upon the other side, as in the

plain arch type; however, the ridge or ridges at the center do not.

There are three types of tented arches:



- The type in which ridges at the center form a definite

angle; i.e., 90 deg. or less.



- The type in which one or more ridges at the center form an

upthrust. An upthrust is an ending ridge of any length

rising at a sufficient degree from the horizontal plane;

i.e., 45 deg. or more.



- The type approaching the loop type, possessing two of the

basic or essential characteristics of the loop, but lacking

the third.



Figures 122 to 133 are examples of the tented arch.















Figures 122 to 124 are of the type possessing an angle.



Figures 125 to 129 reflect the type possessing an upthrust.



Figures 130 to 133 show the type approaching the loop but lacking one

characteristic.



Tented arches and some forms of the loop are often confused. It should

be remembered by the reader that the mere converging of two ridges

does not form a recurve, without which there can be no loop. On the

other hand, there are many patterns which at first sight resemble

tented arches but which on close inspection are found to be loops, as

where one looping ridge will be found in an almost vertical position

within the pattern area, entirely free from and passing in front of

the delta.



Figure 134 is a tented arch. The ridge marked A--A in the sketch

enters on one side of the impression and flows to the other with an

acute rise in the center. Ridge C strikes into A at point B and should

not be considered as a bifurcating ridge. The ridges marked D--D

would form a tented arch if the rest of the pattern were absent.









Figure 135 is a sketch of a pattern reflecting a ridge, A--B, entering

on one side of the impression, recurving, and making its exit on the

other side of the impression. The reader should study this sketch

carefully. It should be borne in mind that there must be a ridge

entering on one side of the impression and recurving in order to make

its exit on the same side from which it entered, or having a tendency

to make its exit on that side, before a pattern can be considered for

possible classification as a loop. This pattern is a tented arch of

the upthrust type. The upthrust is C. There is also an angle at E. D

cannot be termed as a delta, as the ridge to the left of D cannot be

considered a type line because it does not diverge from the ridge to

the right of D but turns and goes in the same direction.



In connection with the types of tented arches, the reader is referred

to the third type. This form of tented arch, the one which approaches

the loop, may have any combination of two of the three basic loop

characteristics, lacking the third. These three loop characteristics

are, to repeat:



- A sufficient recurve.



- A delta.



- A ridge count across a looping ridge.



It must be remembered that a recurve must be free of any appendage

abutting upon it at a right angle between the shoulders, and a true

ridge count is obtained only by crossing a looping ridge freely, with

a white space intervening between the delta and the ridge to be

counted.







Figures 136 and 137 are tented arches having loop formations within

the pattern area but with deltas upon the loops, by reason of which it

is 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.















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 locating the core and obtaining a

ridge count. If this point is secure in the mind of the classifier,

little difficulty will be encountered.



Figures 140 and 141, then, are tented arches because they have two of

the characteristics of a loop, delta and ridge count, but lack the

third, the recurve.







Figure 142 is a loop formation connected with the delta but having no

ridge count across a looping ridge. By drawing an imaginary line from

the core, which is at the top of the rod in the center of the pattern,

to the delta, it will be noted that there is no recurving ridge

passing between this rod and the delta; and, therefore, no ridge count

can result. This pattern is classified as a tented arch. There must be

a white space between the delta and the first ridge counted, or it may

not be counted. Figure 143 is also a tented arch because no ridge

count across a looping ridge can be obtained, the bifurcations being

connected to each other and to the loop in a straight line between

delta and core. The looping ridge is not crossed freely. No white

space intervenes between the delta and the loop. These patterns are

tented arches because they possess two of the characteristics of a

loop, a delta and a recurve, but lack the third, a ridge count across

a looping ridge.



Figure 144 is a tented arch combining two of the types. There is an

angle formed by ridge a abutting upon ridge b. There are also the

elements of the type approaching a loop, as it has a delta and ridge

count but lacks a recurve.











Figures 145 to 148 are tented arches because of the angles formed by

the abutting ridges at the center of the patterns.



Figure 149 is a tented arch because of the upthrust present at the

center of the pattern. The presence of the slightest upthrust at the

center of the impression is enough to make a pattern a tented arch.















An upthrust must be an ending ridge. If continuous as in figure 150,

no angle being present, the pattern is classified as a plain arch.



Figures 151 to 153 are plain arches. Figure 154 is a tented arch.



Figure 155 is a plain arch because it is readily seen that the

apparent upthrust A is a continuation of the curving ridge B. Figure

156 is a tented arch because ridge A is an independent upthrust, and

not a continuation of ridge B.















Figures 157 and 158 are plain arches. Figure 158 cannot be said to be

a looping ridge, because by definition a loop must pass out or tend to

pass out upon the side from which it entered. This apparent loop

passes out upon the opposite side and cannot be said to tend to flow

out upon the same side.







In figures 159 and 160, there are ending ridges rising at about the

same degree from the horizontal plane.



Figure 159, however, is a plain arch, while 160 is a tented arch. This

differentiation is necessary because, if the first pattern were

printed crookedly upon the fingerprint card so that the ending ridge

was nearer the horizontal plane, there would be no way to ascertain

the true horizontal plane of the pattern (if the fissure of the finger

did not appear). In other words, there would be no means of knowing

that there was sufficient rise to be called an upthrust, so that it is

safe to classify the print as a plain arch only. In figure 160,

however, no matter how it is printed, the presence of a sufficient

rise could always be ascertained because of the space intervening

between the ending ridge and the ridge immediately beneath it, so that

it is safe to classify such a pattern as a tented arch. The test is,

if the ridges on both sides of the ending ridge follow its direction

or flow trend, the print may be classified as a plain arch. If,

however, the ridges on only one side follow its direction, the print

is a tented arch.







An upthrust, then, must not only be an ending ridge rising at a

sufficient degree from the horizontal plane, but there must also be a

space between the ending ridge and the ridge immediately beneath it.

This, however, is not necessary for a short upthrust or spike, or any

upthrust which rises perpendicularly.



In connection with the proper classification to be assigned to those

borderline loop-tented arch cases where an appendage or spike is

thrusting out from the recurve, it is necessary to remember that an

appendage or a spike abutting upon a recurve at right angles in the

space between the shoulders of a loop on the outside is considered to

spoil the recurve.



If the appending ridge flows off the looping ridge smoothly in such a

way that it forms a bifurcation and not an abutment of two ridges at a

right angle, the recurve is considered as remaining intact. The test

is to trace the looping ridge toward the appendage, and if, when it is

reached, the tracing may be continued as readily upon the appendage as

upon the looping ridge, with no sudden, sharp change of direction, the

recurve is sufficient. Figures 161 to 184 should be studied with this

in mind.





[Illustration: 161. Tented arch.]



[Illustration: 162. Tented arch.]



[Illustration: 163. Tented arch.]







[Illustration: 164. Tented arch.]



[Illustration: 165. Tented arch.]



[Illustration: 166. Tented arch.]



[Illustration: 167. Tented arch.]



[Illustration: 168. Tented arch.]



[Illustration: 169. Loop.]



[Illustration: 170. Loop.]



[Illustration: 171. Loop.]



[Illustration: 172. Loop.]



[Illustration: 173. Loop.]



[Illustration: 174. Loop.]



[Illustration: 175. Loop.]







[Illustration: 176. Tented arch.]



[Illustration: 177. Tented arch.]



[Illustration: 178. Tented arch.]



[Illustration: 179. Loop.]



[Illustration: 180. Loop.]



[Illustration: 181. Loop.]







[Illustration: 182. Loop.]



[Illustration: 183. Loop.]



[Illustration: 184. Loop.]



Figures 185 to 190 show additional examples of tented arches.



















The reason that figure 185 is given the classification of a tented

arch is because of the presence of all the loop requirements with the

exception of one, which is the recurve. In this pattern appear three

ending ridges. The lowest ending ridge provides the delta, and the

other two by the convention explained previously, provide the ridge

count. It is a tented arch, then, of the type approaching the loop,

with two of the characteristics, but lacking the third, a recurve.

Figures 186 and 187 are tented arches of the same type. A close

examination of these prints will reveal that when the imaginary line

is drawn between delta and core no ridge count across a looping ridge

can be obtained. It must be remembered that the core of a loop may not

be placed below the shoulder line. Lacking one of the three

characteristics of a loop, these patterns must be classified as tented

arches. When figure 188 is examined, it will be noticed that the

recurve is spoiled by the appendage abutting upon it between the

shoulders at a right angle, so it must also be classified with the

tented arches. In figure 189, the only possible delta must be placed

upon the looping ridge, thus preventing a ridge count although delta

and recurve are present. Figure 190 is assigned the classification of

a tented arch. One of the requirements of a loop type is that the

ridge enters on one side, recurves, and makes its exit on the side

from which it entered. This, of course, makes it necessary that the

ridge pass between the delta and the core. It will be noted from this

figure that although this ridge passes between the delta and the core,

it does not show any tendency to make its exit on the side from which

it entered, and therefore the loop classification is precluded, and it

is a tented arch.





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