Why speculate over an unopened letter when a glance at the contents will tell you all there is to know ?" "You are perfectly right," he answered, "if the object of the inspection is to discover who is the sender of the letter.

But that is not my object.

In my case the habit is one that has been deliberately cultivated--not in reference to letters only, but to everything that comes into my hands--the habit of allowing nothing to pass without a certain amount of conscious attention.

The observant man is, in reality, the attentive man, and the so-called power of observation is simply the capacity for continuous attention.

As a matter of fact, I have found in practice, that the habit is a useful one even in reference to letters; more than once I have gleaned a hint from the outside of a letter that has proved valuable when applied to the contents.