THE REGISTER. 39 



of both. The thickness of the layer of fallen snow may be in- 

 dicated in inches and tenths. 



As to the broad column for CASUAL PHENOMENA, although it 

 is desirable, considering the small space the form of the table 

 allows, to employ abbreviations to express the state of the sky 

 and the different meteorological phenomena; nevertheless, we 

 must limit ourselves to a small number, chosen from among the 

 expressions which most frequently occur, such as those found at 

 the bottom of the blank forms. If abbreviations are too much 

 multiplied, we lose in clearness and certainty what we gain in 

 conciseness. A meteorological journal should not resemble a 

 page of algebra, where a badly formed letter or a misplaced sign 

 renders the expression unintelligible. 



For the additional observations the same rule should be fol- 

 lowed. 



In the space mentioned above, periodical and extraordinary 

 phenomena will be inscribed, with their dates and the hour of 

 their appearance. 



Every change of position, or in the condition of the instru- 

 ments, should be carefully entered, with the precise date at 

 which it took place. If there has been none, instruments all in 

 order will be entered. By the side of the indication of the cor- 

 rection of the instruments will be placed, correction applied or 

 correction not applied, according as the observations ctntained 

 in the sheet shall have been corrected or not. The finished 

 sheet will be signed by the observer. 



The reductions, the corrections, and the calculations of means, 

 must be made day by day and at the end of each month with the 

 greatest punctuality. The necessary tables will be placed at 

 hand by the side of the journal, and each observation reduced, 

 and the correction, if any, applied immediately. 



This is not only the least troublesome method, but the only 

 one which permits the observer to control the observations and 

 the reductions, and to discover the accidental errors of the pen 

 and of the reading in the record. 



The observer cannot be too thoroughly convinced that a me- 

 teorological journal which contains only rough observations, is 

 only half made; in this condition it is wholly unfit to serve any 

 scientific purpose. The observations cannot be compared rigor- 

 ously with each other, nor with those of other stations. The 



