supports against which the
springs _4_ and _5_ may rest, when the receiver is on the hook, these
springs _4_ and _5_ being given a light normal tension toward the stop
springs _8_ and _9_. It is obvious that in the particular arrangement
of the springs in this switch no contacts are closed when the receiver
is on the hook.

[Illustration: Fig. 84. Short Lever Hook Switch]

Concerning this latter feature, it will be noted that the particular
form of Kellogg hook switch, shown in Fig. 83, makes two contacts and
breaks two when it is raised. Similarly the Western Electric Company's
makes two contacts but does not break any when raised. From such
considerations it is customary to speak of a hook such as that shown
in Fig. 83 as having two make and two break contacts, and such a hook
as that shown in Fig. 84 as having two make contacts.

It will be seen from either of these switches that the modification of
the spring arrangement, so as to make them include a varying number of
make-and-break contacts, is a simple matter, and switches of almost
any type are readily modified in this respect.

[Illustration: Fig. 85. Removable Lever Hook Switch]

_Dean_. In Fig. 85 is shown a decidedly unique hook switch for wall
telephone sets which forms the standard equipment of the Dean Electric
Company. The hook lever _1_ is pivoted at _2_, an auxiliary lever _3_
also being pivoted at the same point. The auxiliary lever _3_ carries
at its rear end a slotted lug _4_, which engages the long contact
spring _5_, and serves to move it up and down so as to engage and
disengage the spring _6_, these two springs being mounted on a base
lug extending from the base plate _7_, upon which the entire
hook-switch mechanism is mounted. The curved spring _8_, also mounted
on this same base, engages the auxiliary lever _3_ at the point _9_
and normally serves to press this up so as to maintain the contact
springs _5_ in engagement with contact spring _6_. The switch springs
are moved entirely by the auxiliary lever _3_, but in order that this
lever _3_ may be moved as required by the hook lever _1_, this lever
is provided with a notched lug _10_ on its lower side, which notch is
engaged by a forwardly projecting lug _11_ that is integral with the
auxiliary lever _3_. The switch lever may be bodily removed from the
remaining parts of the hook switch by depressing the lug _11_ with the
finger, so that it disengages the notch in lug _10_, and then drawin