ABSTRACT
A consideration of the properties of this matrix will indicate the characteristics and limitations of the lists which may be derived from it. In the first place, it may be well to consider whether the spacing is maximal; that is, whether the lists are optimal with regard to "time errors." A moment's consideration will show the maximal spacing between pairs involving the same item will be maintained if the pairs are arranged in 1-2, 3-4, 5-6, etc., order until the single term is reached, combining the single term with one and continuing the series n — 1, 2-3, 4-5, etc., until the final term (n — 1)-n is reached. A study of the "maximal" list will show that in its arrangement the spacing n-12 is maintained half the time and the spacing n-32 is maintained for the remainder of the time.
