Astronomical and Nautical Collections. 185 



time in 45° N. latitude on the meridian of Skagen, on the level 

 of the sea, and in a vacuum, is to be divided, according to a 

 new Royal decree, into 38 equal parts, each of which is to be a 

 Danish inch, and 12 inches a foot. All other standards are 

 hereafter to be considered as merely subsidiary to this determi- 

 nation, and to have no authority any further than as they agree 

 with it. 



The weight of a cubic foot of water is to be hereafter de- 

 termined by Professor Oerstedt. The Senate of Hamburg has 

 also adopted the same standard. 



Correction. 



The example of a lunar distance, copied into the Third Num- 

 ber of these Collections, from the Appendix to the Requisite 

 Tables, contain^ an error in the tabular logarithmic difference, 

 which was not suspected, and which therefore pervades the other 

 computations, in which that logarithm is employed. This 

 is the true cause of the apparent inaccuracy of the great tables, 

 which, as well as the scales depending on them, are thus vin- 

 dicated from a groundless imputation. 



There is also an inaccuracy in some of the numbers of the 

 example of all the minute corrections, which has tended to 

 exaggerate, in some degree, the importance of these corrections, 

 since they really amount, in the case computed, to about half 

 a minute only, instead of a minute, or to fifteen miles of lon- 

 gitude, instead of thirty : the general tendency of the example 

 is, however, not affected by this error. 



