310 Succinct Review of the Observations of [No. 112. 



the flood tide, and it is therefore impossible to calculate with exactness, 

 the other days re-appearance of ebb and flood tide at Fagol. 



The mean rise and fall during the year was, ... 0* 50 ebb. 



The greatest, 0*97 



The smallest, 0-04 



The greatest difference between high and low water was observed 

 in the West monsoon, and scarcely ever at new or full moon ; so that 

 there accordingly existed no real spring tide : it never exceeded the 

 fall by 1-03 ebb. 



The highest water-mark, on the other hand, was in the East monsoon, 

 especially in the months of May and June. 



The difference in the rise and fall of the succeeding tides is here, 

 as well as at the other stations, deserving notice ; and though the 

 equality of the succeeding rise and falls evidently depends upon cer- 

 tain rules, yet it is not to be traced, at the first glance at least, to th( 

 decrease of the moon. 



The monsoons, and likewise the stand of the sun's solstice probably, 

 exercise a more than common influence on these tides at Onrust neai 

 Batavia. No stream of ebb and flood, properly speaking, was observec 

 any more than at Fagol or Klampsis, the stream which runs cannot be 

 subjected to any certain rule, nor does the rise and fall of the watc 

 proceed with regularity. The stream in all directions is much influen- 

 ced by the wind, and is very trifling, seldom exceeding one mile to one 

 mile and a half. 



According to the observations that have been made, the duration of the 

 rise and fall of the water in December, January, and February, was about 

 twelve hours ; so that there is in one day, only once high water ane 

 once low ; sometimes, however, the water is longer flowing than ebbing. 



In March for some succeeding days, smaller tides were observed be- 

 tween them, which being of very unequal duration ordinarily, were al- 

 ternating in a short rise, succeeding a long one and vice versa. The 

 recurrence of these small tides which first appeared twice or thrice in 

 the month, may perhaps be brought into connexion with the age of 

 the moon ; the number of days they continued decreased about July 

 and August, though sometimes a short tide of one or two hours 

 occurred ; with these exceptions, there was high and low water onlj 

 once in twenty-four hours. 



