Chicago : Engineering and Contracting Pub. Co. · leaf 504
The sides of theblocks were also provided in each side of thecenter with a longitudinal bevelled groove. Thespace between the two grooves forming a centrallongitudinal rib. When laid the tar filled enteredthe spaces between the blocks forming a longi-tudinal triangular key with its apex… … Fig. 6—Culver Block. provide a burnt clay foundation for a wearingsurface of brick, wood, stone, etc. In construct-ing this foundation a layer of large fragments orburnt clay was spread to a depth of 4 or o ins.and rolled. After the large fragments had beenpressed into a homogeneous mass a layer…
Buildings
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