618 ARBORETUM AND FKUTICETUJM. PART III. 



among masses of other trees, grew rapidly tor five or six years, lar exceeding 

 in heigiit the birch, the perfumed cherry, the chestnut, the yew, and the com- 

 mon sallow, planted w ith them, they disappeared entirely after a certain number 

 of years ; the other trees mentioned having become more vigorous, and choked 

 them. Locusts, not planted among masses of other trees, but by themselves, 

 in a single row, exposed to the air on every side, succeed much better ; 

 because it is found from experience that they requii'e a great deal of liglit and 

 air for their leaves and branches, and a great deal of surface soil for their 

 widely spreading creeping roots. M. Mallet had no better success in the 

 Forest of Mareuil, in the department of Vienne, where the soil is moist and 

 aquatic ; nor in the Forest of Chatellerault, where it is dry and sandy. M. 

 Baudrillart concludes b\' repeating what Michaux has stated ; viz. that it is 

 only in a favourable climate, and in a good soil, that the tree attains a great 

 size, even in its native country. In France, and particulai-ly in the neigh- 

 bourhood of Paris, the tree is seldom seen of a greater heiglit than 50 ft. or 

 60 ft. In Germany, the tree thrives in the middle states, attaining a consi- 

 derable height even at Berlin and Munich. In Sweden and Denmark, in 

 favourable situations, it seems to grow nearly as high as it does in France. 



In America, the locust has been planted here and there about farm-houses, 

 and along fences; and, since the forests were in a great measure destroyed in 

 the war of independence, many persons have cultivated the tree for its tim- 

 ber, and have supplied trenails, from the larger trees, to the shipwrights of 

 New York. These plantations seldom exceed the extent of 20 or 30 acres in 

 one place, though several agricultural societies have offered preniiums for their 

 encouragement. Though the locust tree, in its natural habitats, has never 

 been known to be attacked by any insect, yet, about the beginning of the 

 present century, the plantations of this tree in the Uniteil States were generally 

 attacked by a winged insect, which deposited its eggs in the bark ; and the 

 caterpillars produced from them penetrated into the centre of the trunk of the 

 tree, mining it in every direction, so that the trunk became completely perfo- 

 rated, and was easily broken over by the wind. In consequence of the discou- 

 ragement given by this circumstance to planting the locust in America, and the 

 constant consumption in that country of the timber afforded by the indigenous 

 trees, Michaux thinks that the time may come when the locust tree will be 

 more abundant in Europe than in America. This insect is probably the 

 Cossus robinias of Peck. (See Kirby and Spencers Introduction to Entomology, 

 vol. iii. p. 223.) It does not appear, that, in America, a rich soil injures the 

 tree, as has been alleged by Gov. Pownall (see p. 6 1.5 ) ; for Michaux says that, 

 where it attains the largest size, and produces the best timber, in Kentucky and 

 West Tennessee, the land, when cleared, will yield from 30 to GO bushels of 

 maize an acre, for several years in succession, without manure. In America, 

 on the same land where the oak, the hickory, the beech, the chestnut, and 

 the elm attain a large size, the locust does not exceed 40 ft. or 45 ft. in height. 

 This speaks volumes against its value for general cultivation as a timber tree. 



Properties and Uses. A cubic foot of locust wood, newly cut, weighs 63 lb. 

 3oz.; half-dry, 56 lb. 4 oz. ; and, when quite dry, only 48 lb. 4 oz. According 

 to M. Hartig, its value for fuel, when compared with that of the beech, is as 12 

 to 15. For duration, this author places it immediately after the oak, before the 

 larch and the Scotch pine. According to Barlow {IVitlurs's Treatise, \y. 256.), 

 the strength of acacia timber, as compared with fine English oak, is as 1867 to 

 1672 ; the strength of ash being as 2026 ; beech, 1556 ; elm, 1013 ; Riga fir, 

 1108 ; Madeira larch, 1000 ; Norway spar (spruce fir), 1474 ; and teak, 2462. 

 From some experiments made at Brest in 1823, and communicated by Dr. 

 Bowring to Mr. Withers, the weight of acacia was found to be one sixth 

 greater than that of oak; its strength as 1427 to 820; and its elasticity as 21 

 to 9. By experiments made in the yard of the Royal Naval College, com- 

 municated to Mr. Withers by Dr. Inman {Treatise, p. 265.), it appears that 

 the lateral strength of the acacia in resisting fracture is greater than that of 

 the oak in the proportion of I to 0*75. From all these experiments, how- 



