238 Proceedings of Public Societies. [April 1, 



at the other end. These stones, like it lessens the effect of the engine, whilst 



the others, soon get buried in the 

 sand, so as to keep the chains in a state 

 of tension ; and consequently give ad- 

 ditional support to the beacon. Just 

 above the upper clasp are three short 

 spars, forming an inverted triangle for 

 the purpose of supporting more firmly 

 the seats which are fixed to the top- 

 mast, each piece being terminated by a 

 head of light basket-work, in order to 

 render tlie beacon more conspicuous. 

 From the seats down to the bottom of 

 the shaft, are cleats, by whicli, with the 

 assistance of a chain for a man-rope, a 

 sailor, or other person, may easily as- 

 cend to the top of the beacon. 



The beacon is erected on the highest 

 part of the Longsand, so tliat, even in 

 thick weather, persons wiio may be 



every little approximation towards it 

 increases the effect, without in the least 

 adding to tiie cost or expense of working 

 tiie engine. The method of condensing 

 the steam in a vessel separate from tiie 

 cylinder, is generally considered an in- 

 vention of the ingenious Mr. Watt, and 

 has, since his improvemenis, undergone 

 little or no alteration. This method is 

 effected by means of a vessel, distinct 

 from tl)e cylinder, and called the con- 

 denser, into which the steam is allowed 

 to flow at every half-stroke of the 

 double-powered engine, and at every 

 whole-stroke of a single-powered en- 

 gine, and is condensed by a jet of cold 

 water; which water, together with the 

 air that unavoidably penetrates the 

 packing and joints, or is extricated from 



upon the sand will natuialiy, as the the water, is pumped out by means of 



water rises, be directed to it. The dis- an air-pump. When the condensation 



tance from which it is visible in clear is effected, the water, by its superior 



weather without a glass, is about seven gravity, will immediately fall to the 



miles; it being seen from Boston and bottom of the condenser, the air and 



Lynn Knock buoys to the north-east ; 

 from Hunstanton cliff to the south ; and 

 from buoy No. 2, in Lynn Well, to 

 the west. 



The average expense of such a beacon 

 on a sand like ours, seven feet above 

 low-water mark, would be about SQL 



To George Stephenson, of Killing- 

 Korth, Northumberland, for certain 

 Improvements in Steam-Engines. 

 This invention consists of a method 

 or methods of producing a more perfect 

 vacuum than has hitherto been done 

 in the condenser, consequently in the 

 cylinder of a single or double-powered 

 Bolton and Watt's engine, or other 

 engine, where a condenser is used, or 

 where the condensation is performed in 

 a vessel separate from the cylinder. 

 To obtain a perfect vacuum in the 

 condenser of a steam-engine is a desi- 

 deratum of great value, as the want of 



vapour resting upon the upper part. 

 Suppose in this situation the plunger to 

 he at the bottom of the pump and be- 

 ginning to ascend, leaving a vacuum 

 below it, the water in the condenser 

 will flow down and along the communi- 

 cation-pipe through the valve, and fol- 

 lows the plunger so far in its ascent, 

 until the water finds its equilibrium 

 with that remaining in the condenser. 

 Hence, then, this invention consists of 

 a metliod of discharging the air and 

 water from the condenser, by the action 

 of a double pump, in such a manner 

 that the air in its escape from the con- 

 denser meets with scarcely any sensible 

 obstruction from the condensing water ; 

 the air and water being so distinctly 

 separated, that the discharge of the 

 former is effected chiefly by the ascent, 

 and the discharge of the latter by the 

 descent, of the plunger. — Repertorjj. 



PROCEEDINGS OF PUBLIC SOCIETIES. 



HORTICULTURAL SOCIETY. 



Account of a neio Esculent Vegetable, 

 called Tetra^onia, or New Zealand 

 Spinacli. By Mr. John Anderson, 

 Gardener to the Earl of Essex. 



FROM the experience which I have 

 had in the cultivation of the tetra- 

 gonia, in the present year, I can venture 

 to recommend the following treatment: 

 The seed should be sown in the latter 



end of March in a pot, which must be 

 placed in a melon-frame ; the seedling 

 plants, while small, should be set out 

 singly in small pots, and kept under the 

 shelter of a cold frame, until about 

 the 20th of May, when the mildness of 

 the season will probably allow of their 

 being planted out, without risk of being 

 killed by frost. At that time a bed 

 must be prepared for the reception of 



the 



