Proper noun
Petroski (plural Petroskis)
A surname.
Pencils.com. According to Petroski, this system might have been developed in the early 20th century by Brookman, an English pencil maker. Source: Internet
Petroski claims that Conté used integer numbers that started at 1, with higher numbers indicating softer leads, while Thoreau used higher numbers to designate harder leads (Petroski, 1990, p. 157). Source: Internet
Petroski claims that pencil grades vary "depending upon the manufacturer, when the pencils are made, and the source of graphite and clay. Source: Internet
“It’s odd,” said Henry Petroski, a professor of civil engineering at Duke University and a leading authority on engineering failures. Source: Internet