106 PHENOLOGICAL OBSERVATIONS IN 



be taken that such observations taken from a schedule not sum- 

 marized, should be what might have been observed at the 

 station indicated in the heading, and to indicate such a trans- 

 ference the date should be surrounded by a circle with the pen, 

 which would always mean that the observation was not made 

 in the station heading the column, but in a neighboring one, 

 and was taken from a supernumerary schedule. 



Thunder-Storms. — These dates will be entered in their 

 respective columns and opposite the month indicated. They 

 will not be averaged, of course. The number of observation 

 schedules represented in any "region" or general sheet under 

 this head should be noted somewhere on the top margin of the 

 page. 



Accuracy. — Care must be exercised in selecting schedules, 

 the observations of which appear to have been carefully made, 

 neglecting any which give reason for doubt, when selecting for 

 summation on the form within. Great care must also be ex- 

 ercised in copying the figures and entering them, so that no 

 slip may occur. Every entry should be checked. One slip 

 may spoil the effect of all the accurate numbers entering into 

 the summation. In like manner great care has to be taken in 

 adding and averaging the figures, and for this purpose every 

 sum should be done twice (once in reverse order,) so as to give 

 absolute confidence in the accuracy of the work. 



Remarks. — The compiler filling one of these blanks should 

 keep one copy for himself while sending the other to the com- 

 piler-in-chief. 



The set of stations on the right under "when becoming 

 common," must be exactly the same as on the left, under 

 "when first seen." The compiler can enter explanatory remarks 

 in the blank below, and should sign each sheet as a guarantee of 

 its correctness. These sheets will be bound into a volume for 

 each year. 



