VOL. XVI.] PHILOSOPHICAL TRANSACTIONS. 343 



The medium of the Paris burials was allowed by M. Auzout to be 19,887, 

 and that there died 3506 unnecessarily out of L'Hotel Dieu, wherefore deduct- 

 ing the said last number, the neat standard for burials at Paris, will be 1 6,381 : 

 so that the number of people there, allowing but one to die out of 30, (which 

 is more advantageous to Paris than M. Auzout's opinion of one to die out of 

 25) the number of people at Paris will be 491,430; more than by M. Auzout's 

 last mentioned accompt. 



The medium of the said two Paris accompts 488,055. 



The medium of the London burials is 23,212, which multiplied by 30, the 

 number of the people there will be 696,360. 



The number of houses in London appears by the register to be 105,315. To 

 this adding a 10th part, or 10,531, as the least number of double families that 

 can be supposed in London, the total of families will be 115,840: and allowing 

 6 heads for each family, as was done for Paris, the total of the people in London 

 will be 695,076. 



The medium of the last 2 London accounts is 695,718. 



The people of Paris according to the above account is 488,055. 



Of Rouen according to M. Auzout's utmost demand, 80,000. 



Of Rome, according to his own report, 125,000. 



The sum of these three is 693,055. 



So that there are more people in London, than in Paris, Rouen, and Rome, 

 by 2663. 



Memorandum, that the parishes of Islington, Newington, and Hackney, 

 for which only there is any colour of non-contiguity, is not a 52d part of what 

 is contained in the bills of mortality; and consequently London without them, 

 has more people than Paris and Rouen put together, by 1 14,284, 



Description of an Invention, by which the Divisions of the Barometer may be 

 enlarged in any given proportion. By Mr. Robert Hook, R. S. S. and Profess. 

 Geom. Gresham Col. N° 185, p. 241. 



Since the discovery of the alterations in the weight of the atmosphere, by 

 means of the Torricellian tube, there has been several contrivances devised, to 

 render the more minute variations, in the pressure of the air, sensible. 



And first, the wheel-barometei-, invented and published by Mr. Hook, 

 An. 1665, in his micrography: but this did not fully answer the designed exact- 

 ness, both because the mercury being apt to adhere to the sides of the glass, 

 would rise and fall by jerks, or all at once; and because it is very difficult to 

 adjust the apparatus of this instrument ; as also that it is very apt to be out of 

 order, on which account it is at present almost wholly laid aside. 



