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tion, circumstances, or peculiar disposition induces us to make 

 the object of our attention. There are none of the sciences, 

 indeed, in which accurate observations, if made carefully and 

 truly related by an intelligent person, are not extremely valu- 

 able. At the same time it is no less true, that to render any 

 person a perfect observer, he must be not only intimately ac- 

 quainted with the particular science to which his observations 

 relate, but must also possess a competent knowledge of all the 

 others, that so he may be enabled to estimate properly the re- 

 lative importance of the accompanying circumstances, and thus 

 give the closest attention to those which are necessarily con- 

 nected with the phenomenon, rather than to those which are 

 merely accidental and noways essential to it. But while the 

 knowledge of this truth should teach us the utmost caution in 

 employing our observations in the formation of general theo- 

 ries or laws, it should not prevent us from recording, or even 

 publishing them. Neglecting to do so, we deprive ourselves of 

 the only means of ascertaining their accuracy by comparison 

 with others, or of being led to the discovery how we may in 

 future avoid the errors into which we have been incautiously 

 led. I know that great complaint is often made of the use- 

 lessness of multiplying records of observations, and more es- 

 pecially of those made in Meteorology. But the fault com- 

 plained of is principally that animmense mass of observations 

 are given, without any averages or means being calculated ; 

 that no particulars are given as to the accuracy or position of 

 the instruments, and very frequently that the hours of obser- 

 vation are not mentioned. Now these objections do not apply 

 to the observations themselves, but simply to imperfections in 

 recording them. To judge of their value, we require to be 

 informed whether the indications of the instruments are near- 

 ly accurate, or whether they require correction ; whether their 

 position is such as to secure them from extraneous influence, 

 or whether the hours at which the observations were made, are 

 such as experience has shewn to be most proper. For in- 

 stance, a meteorological register may be kept with great care, 

 and yet be utterly valueless for the purposes of science, by the 

 inaccuracy of the thermometer, by its being placed so as to be 



