Talk:Down-the-hole drill

Question
I'm wondering who Mr Burton was, and whether there is a connection with John Henry (folklore). The date (1840s) is about right. The machine John Henry competed with is described as a "steam hammer" but was it powered directly by steam? It might have been a pneumatic tool with the air supplied by a steam-driven compressor. Biscuittin (talk) 21:12, 28 January 2011 (UTC)

Question
I am confused by the sentence "This system could not be successfully used for holes below 6 inches (150mm) and the machines were very expensive to buy and to run." Does the below 6 inches mean diameter of the hole or length of hole? Also, I am surprised that underground mining use is not mentioned in the article since DTH (or ITH) drills are very common in underground applications. — Preceding unsigned comment added by Amanda Desj (talk • contribs) 15:23, 17 October 2017 (UTC)