VOL. LXII.] PHILOSOPHICAL TBANSACTIONS*|S "iSy 



To sail into Judda harbour, or rather road, without a pilot, would be impos- 

 sible for a stranger, there being so many sand banks and shelves of rocks ; but 

 when you are in, it is one of the safest places that can possibly be; you may 

 make your ship fast with any old junk, and there is no danger, though you are 

 surrounded with nothing but rocks and sands. The best bearing for anchoring 

 is the great mosque e. by s. and the extremes of the land from s, by e. to n.n.w. 

 distance from the landing place about 2 miles. Latitude of Judda, ^l" 28' n. 



Longitude ditto, 39° 26' 45* e. Variation of the compass, 1 1° 52' w. 



Latitude observal at Mocha 13° 23' n. Variation of the compass 12° 33' w. 



XIL ^n Easy Method to Distil Fresh Water from Salt IVater at Sea. By 



Capt. Newland. p. QO. 



The materials necessary for this process are the following; a copper or iron 

 pot of 15 or 20 gallons, an empty cask, some sheet lead, a small jar, a few wood- 

 ashes or soap, and billet-wood for fuel. 



First, in order to make the pipe or worm, Capt. N. took as much sheet lead 

 as was sufficient for the purpose, and beat it on a sponge staff to make it round : 

 this done, he was somewhat at a loss for solder ; however he supplied that defi- 

 ciency with good paste and dungerec, or thin canvas, laid well on, and over that 

 a 2d coat of paste and dungerec, and then a covering of small cered line hove 

 close together and very tight round, over which he put a 3d coat of paste and 

 dungerec, which he found was sufficient to keep it from blowing. The next 

 thing was to fix the pipe in the pot or still-head. When he had well secured 

 the pot in the fagong or fire-place, he filled it about two-thirds full of salt water, 

 about 15 gallons, with which he mixed 2 or 3 double handfuls of wood-ashes, 

 and stirred it well together, in order to soften the salt water ; he then fixed the 

 lid (which was made of plank 3 inches thick) in which there are 2 holes, one for 

 the end of the pipe, the other to put in water as occasion requires, without tak- 

 ing off the lid. It must be well observed, that the end of the pipe is not put 

 more than 2 or 3 inches within the still head; for, should it be put loo far in, 

 when the water boils, the bubbles or saline particles get into the end of the pipe, 

 and make the water brackish in the receiver. To prevent the steam from coming 

 out at the plug-hole or lid, he made a kind of mortar, with wood-ashes, salt 

 water, and rope cut very small, and beat well together, and then applied it, 

 which answered the purpose very well. Now the pipe is fixed in the still-head, 

 he next proceeds to carry it through the worm tub, into the receiver. The 

 worm-tub is nothing more than an empty cask, with one of the heads taken out, 

 and in each side a round hole cut, of about 3 inches diameter, for the pipe to 

 pass through into the receiver, which is fixed at a little distance from the tub. 

 The receiver has also a wooden lid like that of the still-head, with a hole in it 



VOL. XIII. P P . - - /ii t„ ^i^-iAfJ 



