Hydrography^ and the Art of Navigation, S3^ 



Both these tables tend to estabhsh a fact with which meteoro- 

 logists cannot be too strongly impressed, that in order to obtain 

 in our climates the mean height of the barometer, it is indispen- 

 sable to admit into the calculation an equal number of observa- 

 tions, corresponding to the winds from opposite directions. 



The tables which we have just transcribed, suggest many* 

 scientific questions ; they lead us to inquire how this influence 

 of winds on the weight of the atmosphere, varies with the posi- 

 tion of places, with their greater or less distance from the sea, 

 with their latitude, &c. In the mean time, till data sufficiently 

 numerous be obtained to enable us to attempt the solution of 

 these various meteorological problems, I shall here present to 

 the reader the results of two series of very accurate observations, 

 which were communicated to the academy by MM. Schuster and 

 Gambart. The first were made at the School of Artillery and 

 Engineers at Metz, the others at the Observatory of Marseilles. 



Observations at MetZy continued for Nine Years, 



mm. 



The difference between the extremes is sensibly less than in 

 the observations at Paris. At the same time, it would be pre- 

 mature to draw general conclusions from this fact, which may 

 perhaps be purely accidental. 



The following seems more decisive : — 



Observations at Marseilles, continued for Five Years, 



