ON A METEOROLOGICAL NOMENCLATURE. <J }f 



be, with accuracy, by such a nomenclature as I have been » 



examining. \ hope, therefore, that my fellow-labourer, 

 whose production I have, in my turn, been criticising, will 

 accede to this principle, that, in forming a nomenclature 

 for meteorology, the terms which it shall be needful to esta-* 

 blish and define (in addition to common words on the sub-» 

 ject) shall be carefully formed from the Latin, in which 

 there exist already a number of words that are perfectly ap- 

 posite. Those who are precluded from acquiring these, 

 may be left, as in olher sciences, to the use of their peculiar 

 synonyms, which the student will find it no very difficult 

 task to attach to their correspondent terms in his own series; 

 for, if I have a just conception of the extent of the vulgar 

 nomenclature, it would form but a limited collection. 



I shall not now enter into every consideration, which has 

 occurred on the perusal of Dr. Bostock's elaborate commu- 

 nication ; but before I conclude I must notice another phe- 

 nomenon, in the explanation of which I differ from him. He Transparent 

 speaks of a transparent condition of the atmosphere, as one a moSi> eie * 

 of the most infallible signs of a change of weather, and as 

 seldom lasting more than a few hours. I am convinced from 

 several points in his description, and particularly from the 

 varnish which it is said to throw upon any large expanse of 

 water, that he intends a condition of the atmosphere, in 

 which, though transparent below, it is more opaque than 

 common in the higher part. There exists in those regions 

 at such times a quantity of water in a peculiar state of diffu- 

 sion, giving a strong milky opacity to the twilight, the re- 

 flection of which occasions the varnished appearance to 

 which he adverts. The whole quarter above the sun, after 

 it has set, has sometimes even a lively pint tinge, and in this 

 case a thunder storm ensues. The lilac or violet band, spread 

 round the horizon, is merely the Colour of the falling dew; 

 and this belongs rather to that perfectly transparent state of 

 the atmosphere, which accompanies our easterly winds in 

 the spring, and is so far from being transient, that there is 

 no state in which it is found to continue for a longer time 



o 



the same. I am, respectfully, thy friend, 



Plaistow, Essex, LUKE HOWARD. 



16M of 6th Month, 1810. 



XII. 



