A STUDY OF THE VENTILATION OF SLEEPING CARS.

Problems of ventilation confront the designers and operators of all enclosed spaces in which one or more persons are expected to live. Demands for a supply of fresh air must be recognized by those operating hospitals, theaters, offices and to a peculiar degree by those concerned in the management of public conveyances, in which the space for each occupant is necessarily restricted. For the purpose of securing a suitable exchange of air in railway cars many types of ventilators have been suggested and not a few have been given practical tests. About three years ago I was asked to report on the efficacy of one of these which had been applied to a few sleeping-cars, which has since been applied to a large number, and which seemed to be of considerable practical usefulness. In this connection it became evident that it would be necessary to establish some basis