50 BUIST ON THE CURIA MURIA ISLANDS. [Jan. 23, 1860. 



mounted gradients of 1 in 25, and even 1 in 23 ; therefore a gradient of 1 in 

 30 could not be considered impracticable. Moreover, stationary engines might 

 be used for limited distances, besides inclined planes, assisted by descending 

 weights of mineral from high elevations. 



The Chairman could hardly agree with Mr. Hamilton in considering that 

 this was a topic which the Geographical Society could not entertain. On the 

 contrary, he thought, with Admiral FitzRoy, that the Society was bound to 

 entertain projects of such vast importance. 



General J. E. Portlock, f.r.g.s., thought it right to correct a small error 

 which had been made. It had been observed that 200 feet in a mile was in 

 the proportion of 1 in 30. The English mile, composed of 5280 feet — not the 

 geographical mile — being that used in engineering calculations, 200 feet in a 

 mile would be a little less than 1 in 26J. This fact was noticed with a view 

 of putting the question on the most fair ground, as 1 in 26^ feet is so nearly 

 the same as 1 in 25, stated by Admiral FitzEoy to have been about the steepest 

 slope effected in American railways. The work, therefore, is doubtless one of 

 great difficulty, but, in the opinion of General Portlock, by no means in- 

 superable. 



Mr. Hamilton explained that he had taken the nautical mile of 6000 feet. 

 According to General Portlock's calculation, the difficulty would be even greater 

 than he had estimated. 



The second Paper read was — 



2. The Curia Muria Islands. By George Buist, ll.d., Cor. f.r.g.s., &c. 



This group, from its many peculiarities always interesting, physically 

 considered, but which, might, if presenting no farther claims than 

 this on our attention, have continued neglected as before, has of 

 late become famous from the treasures of guano it was alleged to 

 contain, and from the large sums of money expended with the view 

 of securing these and turning them to account. Though the manure 

 is only found on two of the smallest of the group — Jebeliyah and 

 Hasiki — it was computed to amount, when they were examined in 

 1852, to 200,000 tons, and it is asserted that 45,000 tons have, up 

 to the end of 1858, been exported. In the beginning of the last- 

 named year there were some 50 vessels at anchor off the islands, of 

 a total freight of probably 45,000 tons. In September, 1857, I saw 

 at Aden 27 vessels destined for the Curia Murias, and freight to the 

 extent of 80,000 in all has probably visited them within the past 

 three years. A man-of-war has generally been in attendance as a 

 survey or guard-ship, and probably not less than a quarter of a 

 million sterling has, within four years, been expended on this ad- 

 venture. 



The officers of the Indian navy are conducting an extended and 

 minute survey of the islands, and will doubtless present us with 

 charts, characterised by the minuteness and accuracy which have 

 hitherto distinguished the labours of that body. Captain Pullen, of 



