Scientific Intelligence, 6fc. 471 



theory of Lyell, which is just that of the sagacious Ray ; and to 

 the explanation presented by Professor Phillips, of King's College, 

 London, as to the remarkable fact, long known, that a rain guage, 

 placed at the bottom of a building, always collects more rain than 

 one placed at the top of the edifice. The inference drawn by him 

 was, " that the whole difference in the quantity of rain, at differ- 

 ent heights above the surface of the neighbouring ground, is caused 

 by the continued augmentation of each drop of rain from the com- 

 mencement to the end of its descent. "—( Tii ird Report of the Bri- 

 tish Association, j). 410.) 



We are indebted to Professor Bache, of Pennsylvania Univer- 

 sity- — (Journal of the Franklin, Institute, Feb. 1836, 106), for 

 the information that the same hypothesis was suggested in 1771, by 

 Dr. Franklin, in a letter to Dr. Percival, published in the Man- 

 chester Memoirs for 1784. Dr. Franklin observes, " I suppose it 

 will be generally allowed, on a little consideration of the subject, 

 that scarce any drop of water was, when it began to fall from the 

 clouds, of a magnitude equal to that it has acquired when it arrives 

 at the earth ; the same of the several pieces of hail ; because they 

 are often so large, and so weighty, that we cannot conceive a possi- 

 bility of their being suspended in the air, and remaining at rest there 

 for any time, how small soever ; nor do we conceive any means of 

 forming them so large, before they set out to fall. It seems, then, 

 that each beginning drop and particle of hail, receives continued 

 additions in its progress downwards. This may be in several ways ; 

 by the union of numbers in their course, so that what was at first 

 only descending mist, becomes a shower ; or by each particle, in its 

 descent through air that contains a great quantity of dissolved wa- 

 ter, striking against, attaching to itself, and carrying down with it, 

 such particles of that dissolved water as happen to be in its way ; 

 or attracting to it ;uch as do not lie directly in its course, by its 

 different state, with regard either to common or electric fire, or by 

 all these causes united. 



" In the first case, by the uniting of numbers, larger drops might 

 be made ; but the quantity falling in the same place would be the 

 same at all heights; unless, as you mention, the whole should be 

 contracted in falling, the lines described by all the drops converg- 

 ing, so that, what set out to fall, from a cloud of many thousand 

 acres, should reach the earth, in perhaps a third of that extent, of 

 which I somewhat doubt. In the other cases we have two experi- 

 ments. 



" 1. A dry glass bottle, filled with very cold water, in a warm 

 day, will presently collect, from the seemingly dry air that sur- 

 rounds it, a quantity of water that shall cover its surface, and run 

 down its sides, which, perhaps, is done by the power wherewith the 

 cold water attracts the iluid, common fire, that had been united with 

 the dissolved water, in the air, and drawing the fire through the 

 glass unto itself, leaves the water on the outside. 



" "2. An electrified body, left in a room for some time, will be 

 more covered with dust than other bodies in the same room, not 



