f 12 ! 



The 5 th column of Table I contains the means of the ba- 

 roinetric pressures for the several lunar hours deduced from 

 observations made during three years. These numbers show that 

 the Lunar Atmospheric Tide at Batavia has two maxima and 

 two minima. The two highest barometric pressures are those for 

 the hours 1 and 13, the hours following the hours of the two 

 passages of the moon through the meridian ; the two lowest 

 are those for the hours 7 and 19, the hours following the 

 hours of the two passages of the moon through the horizon. 

 The means for the hours 7 and 8 are the same, but by the 

 means for the hours 6 and 9 it is evident that the minimum 

 is nearer to 7 than to 8. The means found for each of the 

 years 1866, 1867 and 1868 show nearly the same features as 

 the means for the three years. 



The regularity of the variation of the barometric pressure 

 from hour to hour between the hours of the maxima and the 

 minima is shown by the numbers contained in the 8 th column. 



The difference between the two extremes at the hours 1 and 

 19 is mm .132. The difference between the mean of the two 

 maxima and the mean of the two minima is mm .107. The 

 latter difference was found for St. Helena mm .094; for Sin- 

 gapore mm . 145. 



In order to examine whether any influence of the variation 

 of the distance of the moon to the earth, and of the phases 

 of the moon on the range of the Lunar Atmosperic Tide exists, 

 the means of the barometric pressures on the lunar hours for 

 the days of the apogee and the days preceding and following 

 these have been calculated; the same has been done for the 

 days of the perigee, New Moon, first Quadrature, Full Moon 

 and second Quadrature. 



The differences between the means of the maxima and the 

 means of the minima for these six periods of lunar days are 

 given in Table II. 



