Proceedings of the P olytechnic Association. 909 



brances may be removed from the sidewalk and a better support for 

 each attachment supplied. 



2. These columns are so j^lanted in iron bed-plates, or sills, that, 

 by means of keys at the base of each, they can at any time be adjusted 

 to a true perpenciicular, rendering alignment and steadiness of the 

 road perfectly practicable. Each sill is about two by ten feet on its 

 base, and placed transversely to the line of the road upon compact 

 earth, concrete, or rubble work. Foundations thus constructed will 

 enable the sills to be laid without encroaching upon vaults or sewers, 

 and leave the gas and water pipes each in the undisturbed possession 

 of its own locality. 



3. Upon each iron cross-head fitted to the top of column, and held 

 securely in its place by substantial yet ornamental brackets, is placed 

 a cross-tie of wood, with intervening pads of India rubber, which 

 will serve both to deaden the noise and to prevent crystallization and 

 wear of iron from constant vibrations that would be communicated 

 from the rapid movement of cars. By a simple form of rail-chair, 

 coml^ined with straps, bolts and nuts, the entire cross-head and tlie 

 rails at each column are firmly clamped with the use of only four 

 bolts and nuts, thus rendering the insertion of new ties, new pads, or 

 new cross-heads an easy work. 



4. The rails used on the road will have a depth of twelve or four- 

 teen inches, admitting the use of car wheels with a flange of several 

 inches in width, and will be distinguished for extreme lightness, with 

 ample strength to effectually sustain the weight of loaded cars, the 

 net-work of lateral and diagonal bracing between the rails and tube 

 obviating, in a great measure, all vibrations which otherwise would 

 occur. 



5. The construction of this railway will admit of the introduction 

 of lighter cars than on any other roads ; they will be without platforms, 

 with entrance at the side, and of sufficient length to seat thirty-five or 

 forty passengers ; there being no possibility of a collision with vehi- 

 cles in the street, their bodies may be made more elegant than the 

 present style of street cars, and, as neither mud nor bruising will 

 reach them, they may be preserved externally as well as a private 

 carriage. Yentilation can be provided at bottom and top, through 

 the ends and underneath the seats ; and the windows so arranged 

 that no careless passenger can spit or drop aught on persons below. 



6. Access to these cars being obtained only by stairs leading to 

 station rooms in the second story of buildings along the line, the col- 



