Business must be conducted in epidemic as well as in normal time, and employees must go to and from their places of occupation. In cities where the distance from the residence to the business districts is great, street cars and other public conveyances must be used. Their use undoubtedly increases the number of contacts and leads to a wider distribution of the disease, but, like eating in public restaurants, it is a chance which many have to take. Few places offer better opportunities for exposure than street cars—where people of all grades of intelligence, representing all states of health and degrees of cleanliness and uncleanliness, are crowded closely together, breathe into each other’s faces, and handle the same straps and supports. In Pittsburgh the cars have a seating capacity for from 30 to 50 persons, but during the morning and evening hours they are crowded to capacity, and are commonly seen to carry more than 100 passengers at a time. Here, too, the unkempt, indifferent foreign element is conspicuous, and these people are known to disregard all hygienic teachings. A few days after the appearance of the epidemic the street cars were placarded with warnings against coughing, spitting and sneezing. The cards instructed people who became ill to go home, to go to bed and to remain there until they were well. Later a second order appeared which gave notice that all windows in street cars were to be kept raised six inches and that no heat was to be allowed in the car. The order was intended to improve ventilation, and, for a wonder, it was enforced. During the first few days the weather was fine, warm and clear, and the draught caused by the open windows brought no discomfort; but later the weather became cold and several days of drizzling rain set in. The cars with open windows became very uncomfortable, but the streetcar employees insisted upon obeying the order to the letter. No judgment was exercised by them, and the windows were kept open night and day, cold or warm, crowded or empty, in fair and rainy weather alike, and no heat was allowed to be turned on. Many people preferred standing to exposing their backs and necks to the cold draughts, and it is more than likely that such use of open windows did far more harm than good. As above quoted, Vaughan pointed out that crowding is just as dangerous out of doors as indoors, and it is certain that crowding in cold, draughty cars is dangerous, both from the close contact and because of the added danger of lowering bodily resistance. In an attempt to decrease the crowding on public conveyances the so-called “stagger-hour” system was adopted in New York. Under this arrangement manufacturers and business houses changed their working hours in such a way that the morning and evening travel was spread out and the average number of people carried per hour was proportionately decreased.