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 Arithmetick. 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. By Richard Price, D.D. F.R.S