60 



layer of clay was carried up a dry rubble stone wall, about one foot 

 thick, and outside of this, the earth filling. 



At the base of this rubble wall, which extends one foot below the 

 , grade of the walk, there was laid a tile drain connecting with silt basins 

 at either end of the bridge. 



The last layer of asphalt on the crown of the arch overlaps the thin 

 edge of the puddle wall, and thus carries all water which reaches it 

 outside of the puddle, and directly into the dry wall, whence it finds its 

 way into the drain without coming in contact with the masonry. 



CULVERT ARCH. 



In addition to the above masonry a culvert arch has been constructed 

 in connection with the deer paddock pool, and is located between it 

 and the Battle Pass pool. The foundation is of cement concrete one 

 foot in thickness. The interior work is constructed of gneiss rock and 

 is coursed rubble masonry. The facing is of Ohio and Belleville sand 

 stone. 



WALKS. 



For gravel walks the sub-grade was fixed at twelve inches below 

 the finished grade ; the surface at sub-grade was made to conform accu- 

 rately to the finished cross-section and grade of the walk and thoroughly 

 rolled. Upon this sub-grade seven inches of rubble stone were laid, 

 upon this, two and a half inches of coarse park gravel, and this was 

 followed by one and a half inches of finer park gravel. The depth 

 of stone and gravel at this stage of the construction was ten and one- 

 half inches. The remaining one and a half inches has been, on the 

 walks already constructed, formed of screenings from the McAdam stone. 



A large portion of the walks finished this season have been surfaced 

 to a depth of three inches with tar concrete ; the sub-structure being 

 the same as for gravel walks. 



Two kinds of concrete have been used, one known as the Burlew 

 Patent, in which boiled pine tar is used, and the other the Scrimshaw 

 Patent, in which raw coal tar is used. The concrete is prepared by 

 mixing these tars with gravel or fine broken stone, coal ashes, &c. 



In laying this material any required form is readily given to the 

 walks and gutters. 



Drain tiles of two inches internal diameter were laid under all walks 

 requiring it, at a depth of three feet six inches, and were connected with 

 the walk silt-basins. 



