Weart replies: Historians should work hard to be accurate, and the same applies to those who would criticize historians. What I actually wrote, and which is true, was that in the 1970s the most convincing evidence for rapid climate change came from an ice core drilled by Willi Dansgaard’s Danish group in cooperation with Americans led by Chester Langway Jr. I never said that theirs was the first deep core. The constraints of a brief article, which attempted to cover a great deal of ground, left no space to describe how the drilling campaign was but one stage in a prolonged effort of heroic proportions—an effort that began in the 1950s and continues today. (Attentive readers might have noticed brief mentions in my photo captions.) I have written more about the drilling campaign in the essay cited in the article, available at http://www.aip.org/history/climate/rapid.htm. Those interested in ice drilling history are also urged to review and contribute to the additional but fragmentary information collected at http://www.aip.org/history/sloan/icedrill.
I am glad that Langway and Johannes Weertman have taken the trouble to draw attention to early deep ice drilling developments. Those named in their letter, and the many other institutions and people who contributed to that important task, deserve more recognition than they have received.
