1866. | Astronomical points of Central Asia. 47 
The weight which is to be attached to these corrections, must de- 
pend on the degree of exactness which regulates the scientific labours 
of the brothers Schlagintweit ; but unfortunately, in the volume that 
has been issued, this consideration is not dwelt on, that is to say, the 
probability of errors in the determinations is nowhere alluded to. The 
determinations themselves are not particularised minutely enough, to. 
enable us to estimate their value. 
In order to judge of the correctness of these labours, we bring for- 
ward some examples. Thus, in the determinations of Lé in Ladak, 
the error which should be expected in the latitude would amount to 
30’*. The longitude of Lé was determined by the transfer of one 
chronometer which was rated at Simla on the 15th May, at Lé on the 
17th September, at Srinagar the 24th October; the longitudes of 
Simla and Srinagar are known. The rate of the chronometer should 
have been deduced from the longest transfer occupying 162 days, from 
which, in the main result, a considerable error was to be expected} 
amounting to no less than 7’.5. . Further an error has crept into the 
ealculations of the brothers Schlagintweit which, when corrected, will 
alter their result by 8’ (instead of 77° 14’ 6” it should be 77° 22’ 5” 
east of Greenwich). The correction of the chronometer was determined 
on the Karakoram pass on the 9th of August; by its action from 
Simla (15th May) to Srinagar (24th October) the longitude of the 
pass was determined at 77° 30’ 4”. But corrections of the chrono- 
meter at Lé were also obtained on the 11th July and 17th Septem- 
ber, according to which the determinations of the Karakorafh pass is 
found to be 77° 39’ 5” or, otherwise, differing by 9’. 
* The latitude of Lé was determined twice by polar heights. 
Rely Ma eae tee AUR 4k Sisal TIS 
16th September, Ds ire tea! Sons nia G70 
WIGRHijes so COOoaOCODe | Be 8S 
According to Cunningham, ......... 84° 9’1 
5 Moorcroft, .......-. --. 34° 9/3 
+ The chronometer was rated in the Observatory of Calcutta in March, 
1855 and April, 1857 (pp. 98 and 102). From this it must appear, that the 
probable 24 hourly disturbance of the chronometer on the spot would not be 
less than -ts. In the longitude of Lé, also, one can suspect an error of at 
least sie Pee" — + 29s. From Simla to Lé is a journey of 125 days, from 
Lé to Srinagar 37 days; whole duration of the journey 162 days, 
