Observations on reversionary payments [electronic resource] : on schemes for providing annuities for widows, and for persons in old age; on the method of calculating the values of assurances on lives; and on the national debt. To which are added, four essays On different Subjects in the Doctrine of Life-Annuities and Political Arithmetic. Also an appendix, Containing a complete Set of Tables; particularly, Four New Tables, shewing the Probabilities of Life in London, Norwich, and Northampton; and the Values of joint Lives. The third edition, with a supplement, containing additional observations and tables. By Richard Price, D.D. F.R.S.