Having graduated from Princeton in 1962 with the B.S.E. degree and a concentration in geological engineering, I was interested in the article about Professor Janet Currie *88’s research (Life of the Mind, March 21). The article states that “hydraulic fracturing ... was virtually unknown before 2000.” In my studies of petroleum engineering in 1960 and 1961, hydraulic fracturing was well known even then, and we were taught how it was being widely and effectively used. Our textbook, published in 1956, also describes fracking.

It is a widely held misconception that fracking is a new process. It is not. There are extensive studies, including by the Obama EPA, showing no harmful effects of fracking. It should also be known that the primary materials used in fracking are sand and water. Authors of articles need to be most careful with all of their facts.

James S.M. French ’62
Birmingham, Ala.