- Lady Isabel's Casket, 67, 191.
- L'Arithmétique Amusante, 198.
- Legendre, 175.
- Letter Puzzles, 16.
- Lock, The Secret, 80, 202.
- Locomotive and Speed Puzzle, 147.
- Longbow and the Bears, Capt., 132, 233.
- Lucas, Edouard, 175, 198, 242.
- M'Elroy, C. W., 179.
- Magdalen, Chart of the, 41.
- Magic Square, A Reversible, 149, 243.
- Magic Square Problems, 21, 29, 44, 111, 112, 128, 149.
- Manciple's Puzzle, The, 56, 183.
- Man of Law's Puzzle, The, 34, 170.
- Market Woman, The Eccentric, 135, 235.
- Marksford and the Lady, Lord, 96.
- Maze, The Underground, 79, 201.
- Measuring, Weighing, and Packing Puzzles, 29, 31, 55, 72, 73, 160.
- Merchant's Puzzle, The, 33, 170.
- Merry Monks of Riddlewell, 68, 194.
- Miller's Puzzle, The, 26, 164.
- Miscellaneous Puzzles, 118, 220.
- Mistletoe Bough, Under the, 91, 208.
- Moat, Crossing the, 81, 202.
- Money, Dividing the, 57.
- Monks of Riddlewell, The Merry, 68, 194.
- Monk's Puzzle, The, 39, 172.
- Montucla, 246.
- Motor-Car, The Runaway, 103, 211.
- Motor-Cars, The Three, 147, 242.
- Moving Counter Problems. See Counter Problems, Moving.
- Nash, W., 237.
- Nelson Column, The, 146, 241.
- Newton, Sir Isaac, 248.
- Nines, Plato and the, 154, 247.
- Noble Demoiselle, The, 59, 186.
- Noughts and Crosses, 156, 248.
- Number Blocks, The, 139, 238.
- Numbers on Motor-Cars, 103, 148.
- Numbers Partition of, 46.
- Numbers The Chalked, 89, 206.
- Nun's Puzzle, The, 32, 169.