788 Note on the Nautical Instruments of the Arabs. [Dec. 



tion without duly qualifying himself by consulting his books. It is also 

 clear that the same set of divisions may be made to serve for night 

 observations by placing the eye at d : but as they only embrace alti- 

 tudes exceeding 40 degrees, the instrument would not be applicable to 

 the polar star in equatorial latitudes. 



In conversing with the same muallim on the track taken in different 

 monsoons, I remarked that he always talked of sailing upon different 

 stars, in lieu of different points of the compass, as we should express 

 ourselves. It immediately occurred to me, that this might explain some 

 of the obscurities of the Mohit, where, for instance, that work directs 

 the polar altitude to be found 1\ inches at the " setting of Aquila ;" it 

 might mean that the ship should steer upon the setting point of Aquila, 

 until the pole should be depressed or raised to the altitude indicated. 



I endeavoured therefore to procure an Arabic compass, but not one 

 could be met with in all the vessels — at length mv friend Syed Hosein 

 Sim found a drawing of it in one of the practical works on navigation, 

 (the mdjid kitdb*) in possession of a nakhoda, and without ceremony tore 

 out the leaf to shew it to me, as the captain was afraid of parting 

 with the volume, without which doubtless he would have been greatly 

 at a loss on his return voyage. I immediately made a lithograph 

 drawing of it (fig. 5) exactly as I found it, with the circle of English 

 numbers, shewing it to have been copied from a European card, around 

 which the names by which the Arabs " box the compass," had been 

 entered as more conformable to their own practice. 



These names would seem to point to a time anterior to the inven- 

 tion of the magnetic compass, when indeed the only way of ascertain- 

 ing the relative position of a ship at night in the broad ocean was by 

 observing the points of the horizon where prominent stars rose and 

 set. The system could only have been adapted to intertropical navi- 

 gation, wherein no very great variation occurs in these azimuths, and 

 it is necessarily but an approximation to truth, as hardly any of the 

 prominent stars selected rise or set at the precise azimuth named from 

 them. By the positions assigned to some of the southern stars, we 

 must suppose that it was framed rather to suit places northward of the 

 equator ; but in drawing out the following comparative view, I have 

 thought it preferable to enter the azimuth of each star on an equato- 

 rial projection, when of course the azimuth is equal to the polar dis- 

 tance, and the compass card thus affords to the Arab nakhoda a rude 



■*■ ^\J^<Jo*L« or > as mv Maldive friend facetiously expressed it, the " John 

 Hamilton kitdb'''' of the Arabs. It would be a work of great utility to print au 

 edition of this volume, with emendations and additions suited to the people, who 

 depend upon it as we do on our Greenwich Ephemeris 1 



