Page:William Petty - Economic Writings (1899) vol 1.djvu/270

172 it blows a kind of Storm for some time or other almost every day.

3. That the Snow lies not long in the lower ground of Ireland, Nor doth it freeze more than what it doth in France, Holland, or England. |51|

4. The Rain falling at Dublin and London for the Month October, 1663. was but 20 to 19. That the windiness of the same Month was at Dublin 20. and at London but 17.

5. As for the healthfulness of the Climate, City, or other space of Land; It must be first known how many people are in a certain day living in it, and then the quota pars which die per Ann. for many years together; and for the fruitfulness, how many Births.

6. As to Longævity, enquiry must be made into some good old Register of (suppose) 20 persons, who all were born and buried in the same Parish, and having cast up the time which they all lived as one man, the Total divided by 20 is the life of each one with another; which compared with the like Observation in several other places, will shew the difference of Longævity, due allowance being made for extraordinary contingences, and Epidemical Diseases happening respectively within the period of each Observation.

Wherefore Matters being not as yet prepared for these Experiments, I can say nothing clearly of them; Only, That it seems by the best Estimates and Approaches that I have been able to make, that London is |52| more healthful than Dublin by 3 in 32.

Having said thus much of the Cœlum or Air, or rather of the Ingenium, and way of distinguishing Airs in a better manner than usual: We come next to try the nature of the Soil by the like Expedients.

To which purpose, first know, that the Perch of Ireland is 21 Foot, that of England but 16½; Wherefore the Acre of 160 Perches is as 121 to 196, that is 121 Irish Acres do make 196 English Statute Acres. Now in Ireland a Milch-Cow, if English breed, upon two Acres of Pasture, and with as much Hay as will grow upon ½ Acre of Meadow, will yield