The following Notes afford a mere outline, which the student must fill in by means of experience and reading. Many of the papers in J.I.A. dealing with reversions discuss, in great detail, the formulæ that should be used, and seek for an extreme accuracy which, as has been pointed out by Sir G. F. Hardy, J.I.A., XXX., p. 78, almost defeats its own end. These papers may be interesting to some people, but seem to have little practical value. Probably no two actuaries would make exactly the same deductions from a fund, use exactly the formula, tables and rates of interest, and make exactly the same deduction for costs, etc., but any two actuaries having considerable experience of reversionary transactions would reach approximately the same values. From nearly every point of view there is no “true value” of a reversion; a value only becomes “wrong” if it is so low as to make a purchase at that figure impracticable for any vendor, or so high as to make it impracticable for any purchaser.