Mr.Farey on thelmprovements of Stcam-Engines inCorrewallAil 



from which the deaths have originated, as is done in the Lon- 

 don bills of mortality, distinguishing the sexes. 



It seems necessary that a generalregistry of births, marriages 

 and deaths should be established and enforced throughout the 

 empire, including persons of all religious persuasions: if this 

 were done and the results published, tables of mortality would 

 furnish the means of deducing the actual number of the popula- 

 tion more accurately than any census or direct enumeration, 

 and at all events one method would be a check upon the other. 



The following example will serve to show how a table of 

 mortality might be deduced, if the number of persons alive in 

 the population at every age were known. According to the 

 table, page xv, of the Report of the Census of 1821, there are 

 14.70 males between the ages 20 and 30, and 1155 between 

 the ages 30 and 40, in a population of 10,000 males, since the 

 tenth of these numbers will be very nearly the number of males 

 between 25 & 26, and 35 & 36 ; 



147 : 1 15'5 : : male births 25 years previously multiplied by 

 the probability of a male at birth living 25 years: male births 

 35 years previously multiplied by the probability of a male at 

 birth living 35 years ; therefore 



probability of a male at birth living 35 years 

 probability of a male at birth living 25 years 



= probability of a male aged 25 living 10 years 



1155 X male births in 1796 



1470 X male births in I786 



_ 1155 X male baptisms in 1796 j^g^^.jy 



1470 X male baptisms in 1786' "'* 



The male baptisms in 1796 were! 17,100 and inl786, 100,895 : 

 with these numbers we get -82971 for the probability of a male 

 aged 25 living 10 years. The same probability, according to the 

 table of mortality before referred to, p. 417, line 28, is -8882; 

 and according to the table of mortality given by Mr. Finlaison 

 in the Parliamentary Report on Friendly Societies, 1827, p. 28, 

 is -8777. Similarly if the number living at each age were 

 known, the probability of an individual at every age living one 

 year, might be found, and hence a complete table of mortality. 



LX. On the Origin of the Improvements which have been made 

 in the Performance of Steam-Engines in Corjixmll, ivithin the 

 last seventeen Years. By Mr. Fa rev. 



To llichard Taijlor, Esq. 

 Dear Sir, 



IT is asserted in a communication at p. 323 of your last 

 Number, tiial in my evidence on the patent laws, there are 



statements 



