THE Aures lock differs from the preceding ones in the use of metal
springs, but wooden ones may be substituted; for instance, a wooden spring
like the one in Fig. 209 may be put under the bolt or latch shown in Fig.
219, which is practically the same latch; that is, if you turn the latch
in Fig. 209 upside down it will make the latch shown in Fig. 219; also, if
you take the bolt or lock _B_ in Fig. 219 and make it of one piece of wood
with a spring to it, like the one shown in Fig. 208 or Fig. 209, or make
it exactly like the one shown in Fig. 201, the Aures lock can be made
altogether of wood. But with this lock, as described below, metal springs
were used (Figs. 219, 220, and 221).