3.  We do in the yearly bill reduce the casualties to about twenty-four, being such as may be discerned by common sense, and without art, conceiving that more will but perplex and imbroil the account.  And in the quarterly bills we reduce the diseases to three heads—­ viz., contagious, acute, and chronical, applying this distinction to parishes, in order to know how the different situation, soil, and way of living in each parish doth dispose men to each of the said three species; and in the weekly bills we take notice not only of the plague, but of the other contagious diseases in each parish, that strangers and fearful persons may thereby know how to dispose of themselves.

4.  We mention the number of the people, as the fundamental term in all our proportions; and without which all the rest will be almost fruitless.

5.  We mention the number of marriages made in every quarter, and in every year, as also the proportion which married persons bear to the whole, expecting in such observations to read the improvement of the nation.

6.  As for religions, we reduce them to three—­viz.:  (1) those who have the Pope of Rome for their head; (2) who are governed by the laws of their country; (3) those who rely respectively upon their own private judgments.  Now, whether these distinctions should be taken notice of or not, we do but faintly recommend, seeing many reasons pro and con for the same; and, therefore, although we have mentioned it as a matter fit to be considered, yet we humbly leave it to authority.

Two essays in political arithmetic,
Concerning the People, Housing, Hospitals, &c., of London and Paris.

TO THE KING’S MOST EXCELLENT MAJESTY.

I do presume, in a very small paper, to show your Majesty that your City of London seems more considerable than the two best cities of the French monarchy, and for aught I can find, greater than any other of the universe, which because I can say without flattery, and by such demonstration as your Majesty can examine, I humbly pray your Majesty to accept from

Your Majesty’s
Most humble, loyal, and obedient subject,
William Petty.

AN ESSAY IN POLITICAL ARITHMETIC

Tending to prove that London hath more people and housing than the cities of Paris and Rouen put together, and is also more considerable in several other respects.

1.  The medium of the burials at London in the three last years—­ viz., 1683, 1684, and 1685, wherein there was no extraordinary sickness, and wherein the christenings do correspond in their ordinary proportions with the burials and christenings of each year one with another, was 22,337, and the like medium of burials for the three last Paris bills we could procure—­viz., for the years 1682, 1683, and 1684 (whereof the last as appears by the christenings to have been very sickly), is 19,887.