William A. Radford · Radford Architectural Company · leaf 73
s clean,sharp sand. Sand containing morethan 10 per cent of mud makes a poorjob. Sand may be washed, but it isslow, expensive work. Put together different proportionsof cement, sand and gravel and fill tincans with the mortar. Within a weekexamine the concrete. These experi-ments will teach more…
![An illustration from St. Nicholas [serial] (1873)](https://img.insideoutlibrary.com/img/200/ia-stnicholasserial34dodg-484-612.webp)
