There is no branch of the service here dealt with that has not sent of its best to the fighting line. None will recognise more willingly than you in the trenches that the luck has been yours. We know (you and I) that others have been, by no will of their own, left behind. It is to these, in no small degree, that the safety and equanimity of London have been due. And it is as well that here tribute should be paid to those who have endured without retort the sneers of the malicious and ill-informed as well as the multiplicity of extra duties the war has entailed upon them. One advantage, at least, the war has conferred on you. It has exploded the ignorance of your profession to those thousands of citizens who have elected to share something of your responsibilities. They at least know something of your work; they at least know that the special constable can never replace, though he may assist, the experienced police-officer. You always understood the Londoner; now the Londoner is coming to understand you. I have attempted no more than a sketch of the great machine of which you form part. But if it enlightens the public in some degree as to the way they are served by you it will have achieved its purpose. Yours sincerely, GEORGE DILNOT. London, October, 1915. SCOTLAND YARD. By GEORGE DILNOT. "By all means let us abuse the police, but let us see what the poor wretches have to do."--KIPLING. CHAPTER I. THE SILENT MACHINE. We who live in London are rather apt to take our police for granted. Occasionally, in a mood of complacency, we boast of the finest police force in the world; at other times, we hint darkly at corruption and brutality among a gang of men too clever, too unscrupulous to be found out. We associate Scotland Yard with detectives--miraculous creations of imaginative writers--forgetting that the Criminal Investigation Department is but one branch in a wondrously complex organisation. Of that organisation itself, we know little. And in spite of--or perhaps because of--the mass of writing that has made its name familiar all over the world, there exists but the haziest notion as to how it performs its functions. Perhaps one of the reasons for this ignorance is that Scotland Yard never defends itself, never explains, never extenuates. Praise or blame it accepts in equal silence. It goes on its way, ignoring everything that does not concern it, acting swiftly, impartially, caring nothing save for duty to be done. There is romance in Scotland Yard--a romance that has never been written, that may never be written. It concerns the building up, in the face of incredible obstacles, of a vast, ingenious machine which has become one of the greatest instruments of civilisation the world has ever seen.