A poorly arranged disguise is worse than none at all, for a sharp criminal can almost always penetrate it, and the moment he does it’s all up with you, of course.
For ordinary work full disguises are not necessary.
But a detective should keep a smooth-shaven face and closely-cropped hair at all times, so that by slipping on a false mustache or a wig he can alter his whole appearance. This is about as far as it usually is necessary to go.
Suppose my man who went with the defaulter to South America had depended on a disguise how far do you suppose he could have got without being discovered?
You see the point. A calm exterior at all times and unbounded assurance is better than the best disguise.
Of course if a man is a bit of a ventriloquist it is a great help, but this is a rare gift, and not always to be depended upon even with those who possess it.
Change of clothing will do much. I always carry several hats; they are made expressly for me, and can be stowed away on my person. My usual coat is reversible; so is my vest, but with the trousers you can do nothing in a hurry, of course.
A stand-up collar in place of a turn-down, a colored necktie instead of a black one, a few skillfully-placed lines about the eyes and mouth will change your whole appearance more than you have any idea.
This is about all I’ve got to say on the subject of disguises. It is something every man must learn for himself. The best detectives rarely employ them, but they are sometimes an absolute necessity for all that.
Dave Doyle, at the very beginning of his career, began to show marked ability in making up a disguise.