Paul Frederick, a reporter with the Toronto Star newspaper asked Professor Coleman for his explanation of the Ice Ages,

…"Why were there ice ages?" one naturally asks this greatest of authorities on their spoors.

"Half a dozen theories are suggested he said, "but none is conclusive. I must confess I am not sure. We do know that several times in world history glaciation occurred and there were temperatures so low as to encase with ice this northern continent and even in the tropics bring the ice line down the mountains as indicated [sic previously in the article]. The actual cause I do not know." …

Paul Frederick. "Looking for Tropic Ice,"
The Toronto Star Weekly, April 20, 1935: 12