Blasts from the Past: A look at stories from the pages of National Defense as NDIA and the magazine approach their 100th anniversary.

Oftentimes when thumbing through old magazines, the advertisements are more interesting than the articles. The May-June 1935 issue of Army Ordnance--the predecessor to National Defense--has an ad for a chronograph manufactured by Gaertner Scientific Corp., of Chicago. A chronograph--as anyone with a rudimentary understanding of Latin would guess--was a way of recording time. A strip of paper being pulled by the machine would mark intervals with pin pricks. Precision timing then, as it is today, was vital to military...