500 Mr. John Hogg's Specimen of a 



body, are taken at 9 o'clock in the morning and 3 o'clock m 

 the afternoon ; which hours, perhaps, it would be advisable 

 for any traveller in foreign parts, who intends to keep a daily 

 account of the atmospheric temperature, to adopt for his hours 

 of contemporaneous observation*. 



I have likewise given a specimen of an Abstract, showing 

 in what manner the highest, lowest, and mean temperatures 

 of several principal places in Europe, taken from my Diary^ 

 may be compared with those of London during the identical 

 periods. 



The recent appearance of the admirable " Instructions for 

 making and registering meteorological observations," prin- 

 cipally drawn up by one of the most learned philosophers of 

 this century f, in the fifth volume of the Journal of the Royal 

 Geographical Society, has induced me to lay before your read- 

 ers this short paper ; which, though in itself not very import- 

 ant or valuable, still, I trust, from affording a fair specimen 

 of many accurate observations, may, to the comparative me- 

 teorologist, prove of some little interest ; and more especially 

 as an example to others, who are either about to travel, or 

 to reside abroad |, I hope it may suggest a precedent for 

 keeping a similar diurnal register of the temperature of the 

 weather; because by so doing, we may practically expect to 

 render more certain our present confined knowledge of the 

 laws of climate. 



I remain, Gentlemen, yours, &c. 



London, April 28, 1838. John Hogg. 



* The " Instructions" subsequently alluded to propose the following 

 hours of observation and registry ; namely, 



Morning, 8 a.m. Afternoon, 2 p.m. Evening, 8 p.m. j 



but I would here recommend these as preferable. 



Morning, 9 a.m. Afternoon, 3 p.m. Evening, 9 p.m. 



because the morning's and afternoon's observations may then be compared 

 with those taken out of doors at the Royal Society's apartments in Somer- 

 set House, in London. 



f Sir John F. W. Herschel, at the Cape of Good Hope. 



X I will remark that this may also prove a simple and useful precedent 

 for registering, abstracting, and comparing the degrees of temperature in 

 the more remote counties and districts of the British islands; a much 

 neglected but important subject for inquiry in natural science. 



