In regard to the mail service of Chicago this report can have little to say. Only expert public officials trained in handling the mails are capable of discussing it; and apart from the pneumatic tube or other circulatory system it does not affect our special problem. From motives of economy the Federal Government has incorporated post-offices in the same buildings with United States courts and other public offices. The time has come for a change in this respect, and it is to be hoped that such a building or buildings as this service will need in order to do its great and fast-growing business will be located where needed for post-office purposes, and be designed as to subserve these special functions. The Federal Government should work out a complete scheme for handling the mail matter of Chicago. The location of the central post-office and substations should be determined with a view to economical reception and distribution, all having reference to one another, to the railway mail stations in the city and suburbs, and, as before stated, to the general system of railway circuits. If it be possible to determine the future route of overhead, surface, and elevated street-car systems, they should be brought into the consideration of the Chicago mail service scheme. Strict economy and quick collections and delivery are all involved in this study. The general trend of improvement is in the direction of central plants for heating, lighting, and power, because such plants are found to do the work more economically than separate stations. The individual buildings would, in such a case, cost less initially by leaving out much of the mechanical work now installed; and also they would make saving by greater cleanliness, due to improved atmospheric conditions. For it stands to reason that the abolition of a large majority of the smokestacks of the down-town district would improve the air we breathe, and relieve us of much of the cost of cleaning buildings, inside and out, and of protecting goods. [Illustration: LXXXII. CHICAGO. DIAGRAM OF GENERAL SCHEME OF STREET CIRCULATION AND PARKS IN RELATION TO THE AREAS COVERED BY INDUSTRIES AND MANUFACTURES (RED). THE CENTER OF INDUSTRIES IS INDICATED BY A STAR. RAILROAD PROPERTIES AND LINES IN BLUE. COPYRIGHT, 1909, BY COMMERCIAL CLUB OF CHICAGO ]