IN the interesting discourse reproduced in your issue of March 13 (p. 447), there is a statement that the number of magic squares of order 5 exceeds 60,000. Major MacMahon informs me that he gave ...

These “Hearts” can be in 21 positions in a square of fifth order, and altogether with these “Hearts” in all their positions, I have calculated that there are more than 649,000 squares of ...