360 Scientific Intelligence — Meteorology. 



than those of new moon, it does not follow that more water has 

 fallen at full moon than at the change. The result of observa- 

 tion in that respect is as follows : 



For every 100 days of new moon, there fell 102.9 lines. 

 Do. do. first quarter, do. 102.3 ... 



Do. do. fuUmoon, do. 90.0 ... 



Do. do. last quarter, do. 87-9 ... 



The average quantity for every 100 days is 93.6 lines, whence 

 it appears, that at the new moon, the first quarter, and the full 

 moon, more water has fallen than on common days ; at the last 

 quarter less. The quantity fallen on the total of the lunar 

 phases, surpasses that on other days in the proportion of 98 to 

 93.6. Another question is, whether a change of weather is more 

 liable to happen on the four principal days of the lunar phases 

 than on common days. But it must be decided what is meant 

 by the term change of weather. This term should, the author 

 thinks, be limited to a change from clear weather to rain, or 

 from rain to clear weather, and not be understood to include, 

 as some meteorologists make it, all changes, such as that from 

 calm to windy, or from clear to cloudy, &c. As the author ac- 

 cepts it, the weather must have been steady during two days at 

 least; that i?, that the weather has been clear, or that it has rained 

 more or less during two consecutive days. For example, a week 

 has passed without rain ; it rains on the eighth day, and on the 

 ninth the weather is again fine. In this case, according to the 

 author's definition, there is no change of weather. So also, if it 

 has rained during five successive days, the sixth and seventh 

 must be clear in order to constitute a change of weather. This 

 may be arbitrary, but at least it is not vague, and, if practised, 

 it will prevent, in the balancing of calculations, any leaning to a 

 favourite hypothesis. To avoid another error, into which some 

 have fallen, the author marks no change as occurring on lunar 

 phases, but those which take place on the very day, and never 

 those which may happen on the evening before or on the next day. 

 With these precautions,he finds that, during the thirty-four years 

 or 12,419 days, there have been 1458 changes of weather. Of 

 this number, 105 have taken place at the epoch of the two prin- 

 cipal lunar phases, viz. 54 at the new moon, and 51 at the full 

 moon. Now the whole number of principal phases during the 



