RECORD OF TESTIMONY AND STATEMENTS IN RELATION TO 179 



NECESSITY FOR DISTRICTING PLAN 



minutes ; three times, 41 minutes ; four times, 34 minutes ; five times, 30 

 minutes ; and six times, 27 minutes. 



To obtain a half hour sunshine on the entire surface of the street at 

 the curb level on a north and south street in New York on the shortest day 

 in the year, the buildings must be limited to 3.7 times the street width in 

 height; 45 minutes, 2.4 times the street width; one hour, 1.8 times; an 

 hour and a quarter, 1.4 times; an hour and a half, 1.1 times; an hour and 

 three-quarters, .9 times; and two hours, .8 times. 



Volume of sunshine entering windows 



The volume of sunshine received in rooms is of just as much impor- 

 tance as the sunshine period. A room, for instance, may enjoy direct sun- 

 shine for a considerable period and yet have a comparatively small portion 

 of its cubic contents aerated by direct rays from the sun. The best unit 

 for measuring the effect of sunshine entering rooms is the cubic foot sun 

 hour, that is, a cubic foot of space illuminated by the sun for one hour. 



The amount of direct sunshine entering a window decreases far more 

 rapidly with increased height of buildings than does the sunshine period. 



The data given below for the amount of sunshine is calculated for a 

 window with a pane 32 inches wide and 61% inches long, the opening be- 

 tween the stop beads being taken as 36 by 66 inches and the inside dimen- 

 sions of the masonry being taken as 40 by 70 inches. The room considered 

 is one 14 feet square. The distance between the center of the window and 

 the south wall of the room used in the computation is five feet and the 

 height of the window sill above the floor of the room two and one-half 

 feet. 



The volume of sunshine entering the room through this window, 

 whether obstructed or unobstructed, is shown graphically by the curve in 

 Figure 56. The amount of sunshine in cubic foot hours entering the window 

 is shown by the curve in Figure 58. The cross section of a bundle of sun 

 rays entering this window is shown by the curve in Figure 57. 



At the winter solstice a standard window on a north and south street 

 in New York fulfilling the above requirements and set in a 14-inch wall 

 and situated at a point equal to one-tenth the width of the street down 

 from the top of the buildings on the opposite side of the street enjoys a 

 sunshine period 85 per cent as long as that enjoyed by an entirely unob- 

 structed window. The amount of sunshine enjoyed is, however, only 71 

 per cent of that obtained by an unobstructed window. This disparity be- 

 tween the sunshine period and the sunshine quantity increases with added 

 height of buildings. At a point equal to one times the width of the street 

 below the top of the buildings on the opposite side of the street the sun- 

 shine period enjoyed by a window is 12 per cent of that enjoyed by an 

 unobstructed window though the amount of sunshine is only about one 

 per cent. Here again the thickness of the wall is to a large extent the con- 

 trolling factor. Where the opposite building obstructing the window is a 

 Tow one the disparity between the sunshine period and the sunshine quan- 

 tity is not very much greater in a thin wall than it is in a thick wall. This 

 disparity, however, increases considerably in the case of high opposite 

 buildings. The quantity of direct sunshine admitted by a window, set in 

 a wall 8 inches thick on a north and south street and situated at a point 

 equal to one times the street width below the top of the opposite buildings 

 is 6.5 times that admitted by the same window similarly situated but in a 

 14-inch wall. 



