Xll 



ADDITIOXS AND CORRECTIONS. 



be urged towards the pitce of expansion, until the first wave 

 has reached them, and if the velocity of this wave be great- 

 er in one direction than in another, the effect must be more 

 extensive on that side. Now in the case of the successive 

 expansion of the air by the sun, all the points af expansion 

 move westwards with a velocity of about 1500 feet in a 

 second, which is considerably greater than that of a wave 

 moving upon the atmosphere, or that of sound propagated 

 through it, which is more immediately comparable to that 

 of the effect in question ; consequently the Wave cannot 

 precede the point of expansion, so as to produce any .cur- 

 rent in the more westerly parts ; the current from east to 

 west must, therefore, prevail. But, at the opposite part of 

 the globe, the refrigeration must produce an effect precisely 

 contrary to that of theheat ; the air tending to descend and 

 flow from the parts which are coolest ; the depression not 

 being transmitted to the more westerly parts with sufficient 

 velocity, to produce a current from east to west by these 

 means, the easterly parts only will be affected by a current 

 from west to east, which will probably exactly counter- 



balance the easterly tendency produced at the opposite part 

 of the globe, so that the breezes thus excited must be mere- 

 ly transitory, and in opposite directions. 



P. 463. Col. 2. L. 4 and 5 from the bottom must be 

 transposed. 



P. 471. Col. 1. L. a after the table, for " above " read 

 about. 



P. 481. Col. 2. L. 0. for " charged ", read charred. 



P. 500. In the columns " Refractive force" and " simple 

 refractive power", the numbers opposite to " White wax" 

 and " Oak" should be opposite to " Olive oil" and " White 

 wax", respectively. 



P. 560. Col. 1. L. 39, after" purpose", insert, Mr.Giddy 

 has observed that an equiangular spiral may impel another 

 similar curve without friction: it is indeed easy to see that 

 two such spirals must always touch each other in tlie line 

 joining their centres. 



P 562. Col. l.L.ll,for ";", read, -;. 



L. 5 from the bottom, for " concentrat- 

 ing", read generating.] 



