The effect of humidity , temperature and water content on the strength of concrete

The author has divided the following paper into two portions. The preliminary work was finished by the author in 1917, and is marked "Preliminary Researches." When the author returned to South Africa in 1919, he was fortunate to travel with W. J. Cooper, Esq., the Chief Engineer to the Penarth Cement Works, who brought several facts to the author's attention. Mr. Cooper discussed the use of concrete mixers with the author, and suggested that the water content was an important branch of research in South Africa. The author has tested over 3,000 specimens, and gives these results marked "Further Researches." Ernest John Hamlin