oct.— mAlR. 1859-60.] A method of cooling the Air of Rooms ,SfC. 309 



SELECTIONS. 



On a Method of cooling the Air of Rooms in Tropical Climates. By 

 Professor Piazzi Smith, Astronomer Royal for Scotland. 



Before an inventor can expect to enlist any interest in his la- 

 bours, he must fully state the case to which they lefer, must show 

 that sufficient importance attaches to it, and should give an ac- 

 count of what others have done in the same direction before him ; 

 so that it may be generally understood at what point of the ques- 

 tion he has taken it up, and whether he has really and essentially 

 advanced it. The limits of this article will not allow of these de- 

 siderata being so fully treated of as they deserve, but very few 

 persons in this country having had the opportunity of becoming 

 practically acquainted with the case, of experiencing the intense 

 necessity of some alleviation of the evils which it brings, and of 

 witnessing the imperfect action or the mistaken principles on which 

 the various remedies act which have been attempted up to the 

 present time, some small portion of the space which ought, per- 

 haps, more strictly to be devoted to new matter, may be profitably 

 employed for this purpose. 



The heat which is occasionally felt in temperate climates, can- 

 not call for any serious means of alleviation, as it never rises to a 

 degree dangerous to health, or obstructive to business ; it never 

 lasts long, and there are always means of tempering it, in the cool- 

 ness of the nights and of the winters, as stored up for our use in 

 the earth, cellars, wells, springs and mountains. Nor is the heat 

 of the countries between the temperate and the torrid zones such 

 as to call for much attention ; its general characteristic is dryness, 

 constant blue sky and sunshine ; the heat is felt there as radiation 

 rather than temperature ; the rays of the sun are scorching ; but, 

 in the shade and at night, coolness is to be obtained. Such a cli- 

 mate is very healthy, as is shown by the instances of the Cape of 

 Good Hope and Australia. Working in the open air may perhaps 

 be too severe for some European constitutions, but those whose 



