So many people imagine that anyone and everyone who is engaged in detective or Secret Service work carries about with him a large assortment of wigs, false hair, and other disguises. When any of this work is reproduced on the stage or in moving pictures, or in the pages of works of fiction, disguises of various kinds are generally well to the fore. But, gentle reader, take it from me, who have been through the real thing, and rest assured that any kind of disguise is always attended with danger. To wear false hair or wigs, or even to have them found in your possession, would mean death instantaneously, or at best next dawn, in an enemy country; probable imprisonment in a fortress for many years in a neutral one. The cleverest men I have met in the Service rarely assume any artificial disguise, although I admit that there are exceptional and urgent occasions when its aid must be sought of necessity. In fiction you will perhaps have observed the universal rule seems to ordain that the assumer of disguises invariably endeavours to change his outward appearance from juvenility to old age. That, to my way of thinking, is merely adding to one's difficulties. In real life it will be found far easier to play the part of a person much younger than you really are than it is to play the part of one who is much older. On such rare occasions as I had to make it part of my business to disguise myself I selected for choice the transfiguration of my outward appearance to a younger rather than an older person whenever the circumstances so permitted. For example, I would enter a building to all outward appearances a man of sixty years of age or upwards, and within a very short space of time reappear as a man of not more than thirty. These tricks may be attempted at night in artificial lights, but by daylight the risks of discovery are not worth the small gain or advantage that may be believed to be attained by their aid. The common sailor, or working-man who is badly dressed, very dirty in appearance and who has not shaved for many days, is generally an object which most men avoid and few women find the smallest interest in; whilst he can roam at pleasure in most public places, and if he has the price of a drink in his pocket he invariably gathers around him a multitude of friends ready to tell him anything they may know or to believe any cock-and-bull story as to his own antecedents which force of circumstances or a very vivid imagination may suggest. All disguises and concealments of identity are of little avail unless very thoroughly attempted and carried out. Sir Robert Baden Powell, in his book "My Adventures as a Spy," speaks of the importance of remembering the back view. He writes: "The matter of disguise is not so much one of a theatrical make-up--although this is undoubtedly a useful art--as of being able to assume a totally different character, change of voice and mannerisms, especially of gait in walking, and appearance from behind."