208 



PART III. 



MISCELLANEOUS INTELLIGENCE. 



Art. I. Foreign Notices, 



FRANCE. 



Paris, Jan. 17. 1828. — You shouldnothaveleft France without visiting, 

 and recording the agricultural improvements of, my excellent friend, General 

 La Fayette, at La Grange, who relied on your spending a few days with him. 



Besides the admirable arrangement of 



his farm, and his fine flock of Merinos, you would have greatly approved the 

 substitution of an orchard of 10,000 apple trees, for the vines of an old 

 vineyard, on strong clayey soil. The General has found that, on such a soil, 

 the cider of the apple, properly prepared, is superior to the wine of 

 the grape. The towers of the General's chateau are now thickly clad with 

 ivy, and the grounds around it are laid out a I'Anglais, accordinsi to a plan 

 sketched out, and directions given, by Charles Fox, during his visit of 

 a week at La Grange Ever yours, — Chev. JMnscIet. 



Passage of Hot Air and Smoke through Flues. — Numerous experiments 

 have lately been made in France, for the purj^ose of ascertaining the laws 

 regulating the rapidity with which hot air passes through flues, &c. The 

 results appear to be; — 1. That flues oppose to the passage of hot air a re- 

 sistance proportioned to the length of the pipe, the square of the rapidity-, 

 and in an inverse ratio to the diameter. 2. That the coefficient of friction 

 is not the same with reference to different substances. 3d. That by nar- 

 rowing the superior orifice of a flue, the rapidity of the passage of the air 

 through that orifice, goes on increasing to a certain limit, which is the 

 rapidity resulting from the pressure that takes place at the inferior end of 

 the pipe. 4. That by narrowing tiie inferior orifice of a flue, the body of 

 air passing through (la depense) diminishes solely in proportion to the 

 diameter of the orifice, and consequently that the rapidity in the orifice 

 itself increases in an inverse ratio to its diameter. The two last results are 

 capable of numerous applications to the useful arts. A strong draught is 

 frequently indispensable. Hitherto only two elements have entered into 

 tiie estimate of draught, — the height of the chimney, and tlie temperature 

 of the hot air. To increase the height of a chimney is always attended with 

 considerable expense, and it cannot be heightened indefinitely, and to in- 

 crease the temperature of the hot air costs nuich fuel. It now appears that 

 the diameter of a chimney is also a powerfid element in draught, limited 

 when the superior orifice is fixed ; indefinite when it is not so, and this 

 element costs very little expense. {Lit. Gazette, April 5, 1S28, p. 218. 

 Com. by A. G. near Barnsley.) 



Traiisjjlanting Shrubs in fuU Grotvlh. — Dig a narrow trench round the 

 plant, leaving its roots in the middle in an isolated ball of earth ; fill the 

 trench with plaster of Paris, which will become hard in a few minutes, and 



