490 



Dr. G. Neumaver on the Lunar 



[May 16, 



far and to what an extent such small oscillations as those in question, and 

 which for lower latitudes have already been proved to exist, would make 

 themselves manifest, in spite of the great atmospheric disturbances of 

 higher latitudes. The volume of discussions above referred to contains 

 consequently the results of the reduction and classification of upwards of 

 43,500 hourly observations on pressure of air, registered during the period 

 from the 1st of March 1858 to the 28th of February 1863 ; and in pub- 

 lishing these results I was chiefly guided by the conviction that it would 

 hardly be compatible with the scope of such a work to enter upon a full 

 discussion of the phenomena connected with the lunar influence on the 

 barometer ; while a complete reduction and classification would make the 

 observations apt to be taken up by any one interested in this matter for 

 the purpose of being subjected to a rigorous examination and discussion. 

 While engaged upon this task, I could not fail, however, to be struck by 

 some very interesting facts which, though they are far from being reducible 

 to definite laws, may serve to furnish some connecting links with respect to 

 atmospheric tides, and to give evidence as to the possibility of proving 

 their existence even in as high a latitude as that of Melbourne. A successful 

 attempt at a complete solution of the problem may only be hoped for when 

 a larger number of discussions on barometrical observations, collected at 

 ectropical stations, will be at our command. 



Prior to entering upon the task proposed, it appears desirable to give a 

 few particulars, requisite for a full understanding of the subjoined results. 

 The geographical position of the Flagstaff Observatory was already men- 

 tioned, and it remains only to be added that the standard barometer was 

 one of Newman's construction, 0*400 inch in diameter, its cistern being 

 120-7 feet above the mean level of the sea. A few facts respecting the 

 oceanic tides gleaned from * the Sailing Directions for Port PhiUip,' by 

 Capt. Ferguson (1861), may also find a place here. 



High water at full and change. 



Vertical rise 

 and fall. 





h 



m 



Spring, 

 ft. 



Neap, 

 ft. 





11 



25 



7 



4 



In the midchannel between Pt. Lonsdale and 













1 



50 







At the Lightship, West channel 



2 



10 



4 



3 





2 



25 



4 



3 



At the Bird rock, Geelong 



2 



30 



3-5 



2-5 



At Pt. Gelhbrand and mouth of River Yarra 



3 







4-5 



2-5 



There is no necessity for entering more fully into a description of the 

 method employed in freeing the barometrical observations from the regular 

 diurnal fluctuation and arranging the remainders b — b according to lunar 

 time, inasmuch as this method is quite identical with the one employed 

 by all who have directed their attention to this subject, as General Sabine, 



