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torpilleurs. These had been used by Mr. Naser in the above mentioned 
observations and had proved very satisfactory (see his communication 
in Marineblad, vol. 24), while also at Mr. Cosyn’s bureau they had 
been found to go very regularly. 
Through the kind permission of the Admiralty six of these 
watches have been lent to me, while the Home Office took the 
risks of their carriage to and in the Hedjaz. I here express my 
respectful thanks to their Excellencies the ministers. 
In order to carry these six watches Mr. Naser had had a wooden 
box made with six pigeonholes, which was again to be packed into 
a leather bag to be carried knapsack-wise. This box and this bag 
we were allowed to employ, and transporting the watches in this 
way we could be pretty sure that they were free from disturbance. 
The observations, however, could not be made directly on their 
very low ticks (5 per second) and therefore I had from the Leyden 
observatory the loan of a box chronometer by Cummins. As I have 
said before, however, this chronometer got out of order in Nov. 
1910, and then Prof. BAKHUYZEN sent me another chronometer, by 
Dent, so that the greater part of our observations has been made 
with this one. 
Finally my equipment contained an aneroid-barometer marked: 
Holosteric 7225 with an attached thermometer, a separate thermo- 
meter for the external temperature and a magnetic boussole. The 
correction of the barometer was determined at Leyden, through a 
comparison with the normal barometer of the observatory and was 
found to be —1™™.5 in Dee. 1909 and — 2™™.8 in Aug. 1911. 
No dependence on the reading of the barometer was appreciable and 
so I corrected all my readings with — 2™™.. As corrections of the 
attached thermometer and of the other one I found respectively 
+ 1°.0 and — 0°.5, which corrections have always been added. 
In the beginning there was some difficulty in getting the universal 
instrument well stationed at Jidda. The observations could not be 
made in the open because that would have been very conspicuous 
and we should certainly have been molested by the population, while 
no doubt difficulties would have arisen with the Turkish authorities. 
A fairly large enclosure next to the consulate, which 1 had been 
thinking of, proved to be impracticable, since the ontlook to the west 
was too far intercepted by the consulate. 
So there was nothing else for it but to find a place on the roof 
of the consulate. This seemed to be easy, since here, as everywhere 
else, there was a flat roof offering sufficient room. Such a roof, 
however, rests on fairly thin beams over which matting is spread 
