From a drop of water a logician could infer the possibility of an Atlantic or a Niagara without having seen or heard of one or the other.

It is a capital mistake to theorize before one has data.

I get in the dumps at times, and don't open my mouth for days on end. You must not think I am sulky when I do that. Just let me alone, and I'll soon be right.

Even the best of us are thrown off some- times.

Let me run over the principal steps. We approached the case, you remember, with an absolutely blank mind, which is always an advantage. We had formed no theories. We were simply there to observe and to draw inferences from our observations.

How sweet the morning air is! See how that one little cloud floats like a pink feather from some gigantic flamingo. Now the red rim of the sun pushes itself over the London cloud-bank. It shines on a good many folk, but on none, I dare bet, who are on a stranger errand than you and I. How small we feel with our petty ambitions and strivings in the presence of the great elemental forces of Nature!

It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth.