  A recent paper proposing a model of the limiting speed of the domino effect
is discussed with reference to its need and the need of models in general for
validation against experimental data. It is shown that the proposed model
diverges significantly from experimentally derived speed estimates over a
significant range of domino spacing using data from the existing literature and
this author's own measurements, hence if its use had had economic importance
its use outside its range of validity could have led to loses of one sort or
another to its users.
