to the Antarctic Regions. 189 



successive high waters ; and these must be reduced with a proper 

 allowance for the age of the moon ; that is, not only for the time of 

 the moon's transit, but also for the semimenstrual inequality. The 

 things to be observed are, the mean solar time of high water, the rise 

 of the tide from low to high water, and, if convenient, the mean solar 

 time of low water. 



2. It is desirable to ascertain the existence and amount of the 

 diurnal inequalities in such situations as have been spoken of. For this 

 purpose the heights of high water should be observed for several suc- 

 cessive tides, day and night ; and, if possible, this should be done 

 when the moon is at her greatest declination, or a few days later ; 

 at any rate, not when the moon is in the equator, nor a few days 

 after that period. 



It is very probable that a diurnal inequality of the heights will be 

 detected ; but it appears not worth while to attempt, under the cir- 

 cumstances, to detect a diurnal inequality of the times. 



4. Meteorology. 



A complete meteorological register will of course be kept in each 

 ship during the whole continuance of the voyage ; skeleton forms 

 for the arrangement of the observed and reduced quantities are fur- 

 nished. These are adapted for intervals of observation of six hours 

 throughout the twenty-four ; and although hourly observations be 

 made, as is undoubtedly to be desired, yet the regular entry and 

 reduction of the observations for the hours in the skeleton forms is 

 nevertheless essential, for the sake of future comparison with those 

 similarly entered and reduced at the fixed stations. But in consider- 

 ing the suggestions which it may be proper to offer upon this branch 

 of the subject, the Council have been induced to take a more com- 

 prehensive view than might at first be supposed to be called for by 

 the immediate objects of the Expedition. So many references have 

 lately been made to them upon the subject of directions for meteoro- 

 logical observations, that they have embraced the opportunity of 

 proposing a plan of extensive co-operation applicable alike to the Ex- 

 pedition, to the Magnetic Observatories about to be established, and 

 to other Observatories for which directions have been thus solicited. 

 The Council have therefore thought it more convenient to draw up a 

 separate Report, which, as regards the Antarctic Expedition and the 

 Magnetic Observatories, may be considered as supplementary to the 

 present one. 



In the way of general remark on this subject it may be observed, 

 that it is impossible to pay too much attention to the zero points of 

 the instruments, especially the barometer. Every thermometer and 

 barometer, furnished both to the ships and for the observatories, will 

 in the first instance have been carefully compared with those of the 

 Royal Society ; and one barometer in each ship should be conti- 

 nually referred to as a standard, whenever the instruments are landed 

 and on their return on board, so as to detect and take account of 

 any change which may have occurred in the interval : while the two 



