Improvingly

1856, Eliza Edmondston, Sketches and Tales of the Shetland Islands, Edinburgh: Sutherland & Knox, Chapter 12 “The Fowler,” p. 140, […] so fascinating and exciting is this method of idling away time which might be much more profitably and improvingly employed, that many of the fishermen frequent the cliffs, and peril their lives in the forbidden pursuit.

1927, H. G. Wells, Meanwhile, New York: George H. Doran, Book II, “View,” § 10, p. 222, There are no newspapers and the broadcasting is given over to twaddle—there was a fellow gassing most improvingly about ants and grasshoppers yesterday—mixed up with slabs of biassed news and anti-strike propaganda.

Technology refines slaughter into benign surgery: Kipling calls the abattoir an “operating-room.” Nature has been improvingly obliterated by the machine.