I was much struck by the fair and impartial manner in which the inspector elicited the facts of a case before accepting a charge. Always polite, with no leaning to one side or the other, he endeavoured by careful questioning to elicit whether an arrest had been made on reasonable grounds. There was no bullying, no taking it for granted, except in an obvious case of drunkenness, that a charge was proved. I have, perhaps, not made clear the distinction between reserve men at a station and reserve men in a division. The latter do ordinary duties, and are the first called upon in the event of emergencies anywhere in London. They receive a small sum in addition to their ordinary pay. The former are men who, instead of doing eight hours' duty in the street, do it at the station itself, and are available for any sudden contingency that may present itself within the subdivision. The personnel of the London police is, as I have indicated, selected and tested under the most rigorous conditions. No less relentless in the search for efficiency are the promotion conditions. The Commissioner is an absolute autocrat so far as promotion is concerned, though, in practice, he usually acts upon the recommendation of the superintendents. A constable, before he is promoted, must serve at least five years--in practice, the average is eight years--and must then pass two examinations. One of these is set by the Civil Service Commissioners to test his education, the other is an examination in police duty before a board of high officials. Should he be approved then for promotion he is immediately transferred to another division. These examinations are carried out at every step in promotion. In the words of a keen American observer: "That such a system is successful in bringing to the front the best men available, that it is carried through without favouritism or political considerations, that, in its fairness and justice, it has the confidence of the uniformed force is a splendid commentary not only on the integrity of the Commissioner and his administrative assistants but on the stability and sound traditions of the entire department." CHAPTER XI. THE RIDDLE DEPARTMENT. The perpetual solving of riddles is one of the commonplace duties of Scotland Yard, not only in the C.I.D., but in every branch of the business. Luck may, and sometimes does, help a detective to solve a mystery; but luck never helps to quell a riot or maintain order on the King's highway in times of stress. It is for such matters as these that they keep a Riddle Department at headquarters. They call it the Executive Department, but no matter--as Mark Twain would say. It is there to supply the answers to the conundrums that are always cropping up in police work.