44: SPECIAL DIRECTIONS. 



(d) Integers omitted when the same as in the entry next 



preceding in the order of time. 



(e) Integers omitted except where they are different from 



the usual ones at the place of observation. 



(f) Integers inserted occasionally and apparently without 



any system whatever. 



(g) A constant suppressed, and the excess or deficiency 



recorded, as + or — . 

 The proper mode is that indicated by (a). 



4. Dwersity in the mode of recordiny the Tliermometer, when 

 it is below zero, as follows : — 



(a) Indicated by the sign minus — placed before it, thus 



— 16°. (This is the proper mode.) 



(b) Indicated by the same sign placed after it, thus 16° — . 



(c) Indicated by writing it under a zero^hus -^• 



(d) Indicated by writing it after a zero, with a comma 



between, thus 0,16°. 



(e) Indicated by the word 'below,' or the abbreviation b 



written before or after it — thus 16° below, 16° b, 

 b 16°, or below 16°. 

 The first (a) is the proper mode. 



5. Departure from the printed instructions in recordiny the 

 deyree of cloudiness, some observers reversing the figures and 

 using 10 to denote a clear sky and 0, one entirely overcast ; 

 and others omitting the record altogether in the columns of 

 cloudiness when the sky is clear, and in place of it sometimes 

 inserting the word "clear" in the columns of " Remarks," or 

 elsewhere. Both lead to error, and should be avoided — the zero 

 should always be inserted "in the narrow column," as directed, 

 when the sky is clear. 



6. Diversity in the use of the character zero (0) in recordiny 

 the motion of the clouds, as follows : — 



(a) Used to signify a calm, or that there is no perceptible 



motion. (This is the correct use.) 



(b) Used to signify that the sky is clear, instead of insert- 



ing it in the proper column. 



(c) Used to signify that no observation was taken. 



