687 
With reference to the Jupiter tables of the first kind he says on this 
head: “Die Regel, welche der Verfasser unserer Tafel bei der Berech- 
nung der Daten befolgte, lässt sich nicht klar erkennen; dagegen 
ist es nicht schwer, das Bildungsgesetz der Längen festzustellen” *). 
In the tables of the third kind the way to find the dates seems to 
be indicated by the accompanying column of time-intervals; but here 
also difficulties arise. For if from the synodie period belonging to 
the Babylonian values 398.890 the mean value of the time-interval 
45°14! — 454.233 is subtracted, 3534.657 results, hence not a lunar 
year of 3544367 but 04.71 less. The excess of the synodie period 
beyond the each time tacitly added 12 lunar months is only 444.52, 
this should, therefore, have been added each time to the pre- . 
vious date, instead of 454.23. Moreover the nature of the Baby- 
lonian calendar renders it difficult to calealate the dates in this 
way. The months'have as a rule alternately 29 and 30 days, but 
occasionally a day must be added (in 30 lunar years 14 days), some- 
times, therefore, 2 months of 30 days follow one another; and by 
this irregularity the whole scheme of calculation, which looks so 
simple, is upset. Moreover, in the fact that the dates are given in 
days only, without subdivisions, lies an indication that they were 
found in a different and simpler way. Kuverer points out that 1 
Jupiter period is the same as 138 Babylonian months + 15 days all 
but */,,, day or also = 13'/, Babylonian months + 07.28, che same 
0.23 which occurs in the mean value of the time-interval 454.23, 
and that, starting from this principle, a continuous Jupiter calendar 
might he made, without regard to the yarying length of the months. 
If errors of a single day remained, this was not of consequence for 
the object of the planet tables *). In how far these surmises were 
true will appear from the following. 
II. 
It would seem a priori to be improbable that the column containing 
the time-intervals so carefully worked out should not have 
been made use of at all in the calculation of the dates. We can 
moreover put this to the test. The difficulty here lies in the un- 
certainty as to how long each of the months was which lie between 
two successive dates. On this account we will leave this point for 
the present undecided. In the following table, a portion of the Jupi- 
ter table of the 3'¢ kind Sp. I 46, the successive dates- (2"4 station- 
1) Kuverer, Sternkunde u. Sterndienst in Babel. 1. S. 121. 
2) Kuvarer. l.c. S. 166—169. 
