222 ANNUAL OF SCIENTIFIC DISCOVERY. 



MOORE'S SPHERICAL, OR GREAT CIRCLE INDICATOR. 



This instrument, which is another, and a great step towards simpli- 

 fying that most troublesome, but most important problem of great 

 circle routes, consists of four graduated circles of eleven inches diam- 

 eter ; two of which, arranged in opposite planes, represent a meridian 

 and the equator, and over these, two others, by a most ingenious 

 arrangement, are made to revolve in every direction, so that by two 

 attached compasses, or graduated circles, every element of spherical 

 trigonometry can be readily ascertained by inspection, to a great degree 

 of accuracy : a process also adapted to those problems necessary in 

 nautical astronomy. 



DRAINAGE BY MEANS OF A SYPHON. 



Calhorn Loch, in Scotland, was drained more than 100 years a<p 

 by a drain or cut, in some places 36 feet deep. That operation still 

 left about eight acres of water, above sixteen feet deep in the center, 

 and fully twenty acres of marshy ground, which could not be drained 

 without more fall than the whole cut could afford. This marsh has 

 long been considered an eye-sore, but the expense of deepening the 

 outlet, in some places through quicksand, seemed so difficult and ex- 

 pensive, that although often talked of, the operation was never under- 

 taken. A plan has, however, been recently adopted, which it is believed 

 is new in the annals of draining, at least on so great a scale as in the 

 present case, viz. by means of a large syphon. This syphon is exactly 

 half a mile long and seven inches in diameter. It has now drawn olf 



9 feet in depth of the water in the loch, which it is expected will give 

 fall to enable the proprietor to drain properly the marsh already 

 referred to, and reduce the loch to an ornamental pond. The highest 

 part of the syphon is 21 feet above the present surface of the lock, 

 and the longest limb is 10 feet under the level of the water, giving 



10 feet fall. The main part of the syphon consists of cast-iron pipes 

 5-8ths of an inch thick, with spigot and faucet joints very carefully 

 joined and made air tight with lead. The contract price of the iron- 

 pipe laid and complete, was 7s. 6d. per yard. 



SPEED OF CLIPPER SHIPS. 



The recent arrival at New York of the clipper ship " Sovereign of 

 the Seas" in 82 days from the Sandwich Islands, and of the " Comet" 

 from San Francisco in 83 days, has called forth a report from Lieut. 

 Maury to the Secretary of the Navy on ships and ocean routes, from 

 which we make the following extracts. Speaking of the former ves- 

 sel, Lieut. Maury says : Returning from the Sandwich Islands to New 

 York in the remarkably short run of eighty-two days, she passed 

 through a part of the " Great South Sea," which has been seldom 

 traversed by traders at least I have the records of none such. Little 



