Page:Popular Science Monthly Volume 89.djvu/858

 R44

��Popiihir Srifure Miitilli!//

���The Old-Fashioned Heavy Paving-Block Gives Place to a New Form

ANEW type of granite block pave- ment, almost as smooth and as easily cleaned as asphalt, is finding favor as a wearing surface for streets of dense traffic. Instead of hea\y rectan- gular blocks seven and eigiit inches deep, the new practice is to spccif\- cubical blocks of from three and a J half to four inches, the deptii of • the ordinary brick.

The new tyjie is laid in con centric interlocking rows, called the oyster-shell pattern. He- cause of sniallncss of the block and the apparent irrigularil) of joints, a gond foothold for horses is obtained. Another advantage is that opposite wheels of the vehicle are not on the same course, thus lessi-ning shod. and nnir<- ev<-nly (lis tributing the lo.id on the base. The small block also al- lows more of the <l<-plh of the pave- nietit to be matle up

��ofsubstantialand comnara- tively cheap concrete base material.

The method of laying the blocks as followed on the new Brooklyn -Brighton \ iaduct ill Cle\cland, Ohio, is typical. They are laid in a cushion of dry sand and cement, mixed in the pro- portions of three parts of sand toone of cement on the concrete base. What is laid one day is thoroughly wet- ted down at night so that the blocks are made prac- tically integral with the base. The joints between the blocks are then filled with a mortar of one part of fine sand to one part of cement. In Cleveland the contractor is paid §2.50 per square yard for labor and material for the cushion, blocks and grout. The cost of base will depend on its depth. Small granite cube pavements have been used extensively in many English and European cities as well as in South America for several vears.

��The new type of gran- ite block pavement is laid in concentric inter- locking rows, called the oyster-shell pattern

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��Simply urnsp the linndlchiirs. pick out some imuKinary object on the distant horiion and expend your energy in an effort to catch it

��Marathoning at Home on a Special Tread Mill

I .\NT.\c; a marathon at home is not as dillicult as it sounds, machine has been devised which makes it easy for the runner, including the fat man who wishes to reduce by adopting this form of exercise, to run at home any lumber of miles he ilesires. The machine as illustrated consists of a wooden tread tightly drawn over rollers. The whole apparatus is >iipporled on .slcH.>l legs, and when not in use can be folded ii|). H.uullebars en- able the rimner to exert an addition. il force while he i.^ run- ning, and i>re\ent him from falling off.

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