I've just realised that the above post may not make much sense to people who are too young to know about typewriters! With the typewriter there was a semi-circular area between the keyboard and where the paper was which was called the typing basket. When you hit a key on the keyboard a metal arm with a small hammer head shaped piece on the end came up out of the typing basket and hit the paper, making the appropriate letter. Each of the hammer head shaped pieces had on it two characters, e.g. a lower case letter "a" and an upper case one so you would have 40 or so of these arms flipping up and down in turn as your typed, an ideal attraction for a cat.