_I_. I mean that the motor-omnibus driver, sitting as he does in front
of his vehicle and manipulating his steering-wheel like this, can
do little or no harm to the apparatus. On the other hand, the
steam-roller mechanic, standing _inside_ the body of the vehicle, and
having the steering-wheel in _this_ position--

_He_. On the sofa?

_I_. Naturally. Well, supposing he happens to have a slight difference
of opinion with his mate as to which of them ought to do the driving,
the wheel is quite likely to be pushed off on to the macadam, where it
gets a trifle frayed round the edges.

_He_. I see. How awfully stupid of me! And this pouffe, or whatever
they call it?

_I_. Week in and week out, boy and girl, I have seen that dromedary
ridden over more miles of desert than I can tell you, and never once
have I known it under-fed or under-watered, or struck with anything
harder than the human fist. Of course the hump does get a little
floppy with frequent use, but considering how barren your Sahara--

_He_. Quite, quite. I was just looking at that armchair. Aren't there
a lot of scratches on the legs?

_I_. Have you ever _kept_ panthers? Do you realise how impatiently
they chafe at times against the bars of their cage? Of course, if you
haven't....