If press-buttons or contact-keys are placed on the sashes of the windows, the posts of the door, or the treads of the stair, so that when the window or door is opened, or the tread bends under the footstep, an electric circuit is closed, the alarm will be given. Of course, the connections need only be arranged when the device is wanted.
I will not portray the evening dresses that it sometimes takes a kindly husband an hour to fasten, with "press-buttons" and hooks and eyes; and poor Vivie had no husband and depended on her suffragette maid because at all costs she mustn't look dowdy or the woman's cause might suffer at Mrs. Pethick Lawrence's receptions.
In this way, as long as the button is pressed by the operator, the hammer will continue to tap the bell and give a ringing sound. Press-buttons are of various patterns, and either affixed to the wall or inserted in the handle of an ordinary bell-pull, as shown in figure 86.