ON PROPAGATING FRUIT TREES BY ABSCISION. 



135 



A NEW SPECIES OP ROOF. 

 Continued from page l4. 



The roofs are much flatter than for 

 slating, (thecommon proportion being one 

 .foot in height to twelve in breadth,) the 

 couples are no more than three inches in 

 breadth by one and a half deep, and upon 

 these are laid half inch deals, dressed 

 with a plane on the edges, so as to pre- 

 vent intervals at the joints; and the ex- 

 ternal covering is sheathing paper. The 

 sheets are prepared by being dipped in 

 tar, at nearly the boiling point, that it 

 may the more readily penetrate, and 

 after drying for two days, are again dip- 

 ped in tar at a lower temperature ; they are 

 then nailed on the roof in the same man- 

 ner as slates, overlapping each other ex- 

 actly in the same manner; and, above the 

 whole is laid a coat of tar, boiled to the 

 consistency of pitch, on which fine smithy 

 ashes are passed through a seive while 

 cooling to diminish the combustibility, 

 and to prevent the liquefaction of the 

 tar. Mr. William Ramsey, a chemist, of 

 Glasgow, is related to have used, instead 

 of common tar, the tar extracted from 

 wood, in the formation of pyroligneous 

 acid, and, by a peculiar composition, to 

 have made it assume as close a texture 

 and as bright a polish as marble. 



Observations. — The species of roof 

 here described, will soon be extensively 

 adopted where wood and slates are 

 scarce, provided its durability can be 

 ascertained. The building in Greenock, 

 thus roofed, which has lasted twenty 

 years, affords a presumption in its favor; 

 "but we cannot recommend it till it has 

 stood the test of repeated experiments. 



MANGANESE USED IN THE MANUFACTURE 

 OP IRON AND STEEL. 



In the Annales de Chimie, M. Gaze- 

 ran has given a paper on the subject, in 

 which he states that in the German 

 founderies, particularly about Nassau- 

 Siegen they used the black oie of manga- 

 nese with the iron ore in making steel; 

 he advises that from 4 to 5 per cent, of 

 manganese should be mixed with the ores 

 that do not contain it naturally, and states 

 that the best German steel contains 2.16 

 per cent, of manganese and 1 of carbon. 

 It is proposed to use manganese with iron 



stone in the manufacture of crude iron, •" 

 various proportions according to the na- 

 ture of the ore. 



It 



PROPAGATING FRUIT TREES BY 

 ABSCISION. 

 Continued from page 15. 



is conceived that a longer period 

 would be necessary to succeed with this 

 operation in Europe, because vegetation 

 is so much slower here than in India, 

 where Dr. Howison, made his experi- 

 ments; but he thinks that an additional 

 month would be adequate to make up 

 for the deficiency of climate. 



The advantages of this method are 

 stated to be, that a farther growth of 

 three or four years is sufFicient, when 

 the branches are of any considerable size 

 to bring them to their full bearing state; 

 whereas, eight or ten )'ears would be 

 otherwise necessary. This he saw prov- 

 ed from experiment at Prince of Wales* 

 Island. The writer's experience does not 

 allow him to speak of the success with 

 which this method might be applied to 

 forest trees, but he little doubts of its 

 succeeding, and the adoption of it is re- 

 commended at all events in multiplying 

 such plants, natives of warmer climates, 

 whose seeds do not come to maturity in 

 this country. He has besides frequent!}" 

 remarked that such branches of fruit-trees 

 as were under the operation of abscision 

 at the time of bearing, were more laden 

 with fruit than the rest of the tree, 

 which is attributed to a plethora or ful- 

 ness, occasioned by the communication 

 between the branches and trunk being 

 cut off by the division of the bark, and 

 has observed that the roots from a branch 

 under this operation were longer in 

 shooting into the ball of straw when the 

 tree was in leaf, than at another time, on 

 which account he recommends the spring 

 as the best season for makingexperiments. 



Observations. — This mode of jiropa- 

 gating trees, which prevails in many parts 

 of Eastern Asia, is deserving the notice 

 of our horticulturists at home; and from 

 the prevailing inclination to pursue that 

 branch of science, we have no doubt of 

 being soon able to communicate experi- 

 ments of this mode of propagation in our 

 own country. 



