Results of Experiments, on the transverse Strength of Timber, made at Mr. Atkinson's, Grove End, St. John's Wood, on Thursday, March 12th, 1818.

The pieces were each an inch square, except No. 3., which was only 8-10ths of an inch in breadth. The numbers in the Table show the weights it would have borne if it had been an inch square; the pieces were supported at each end, and were loaded by putting 5 lbs. at a time into a scale suspended from the middle; · the distance between the supports 30 inches.

145 lbs. 80 lbs.

93 lbs.

60 lbs.

65 lbs.

125 lbs.

212 lbs. 253 lbs. 295 lbs. 222 lbs. 231 lbs. 212 lbs.

2.25inch. 3 inches. [2.75 inch. 2.5 inches 1.4 inch. 1.3 inch.

As the strength of small pieces depends much on the position of the annual rings, the pieces were placed as nearly alike in this respect as possible. When the pieces were in the position in which they were broke, the dark lines or portions of the annual rings that appear in the section of a piece were vertical. - . From the results exhibited in the preceding Table, it appears very clearly, that Larch is best adapted to resist the force of a body in motion; but to leave no doubts in this respect the following experiments were made.

Experiments on the Resilience of Timber.

The pieces were each an inch in depth, and laid upon supports thirty inches apart. The weight fell between two vertical guides (similar to a pile engine), upon the middle of the piece.

On

No. 11 was a dark-coloured and apparently very strong piece of wood; specific gravity 0.872 or 544 lbs. per cubic foot. * the whole, then, it appears, that Larch is superior to oak in stiffness, in strength, and in the power of resisting a body in motion (called resilience): and it is inferior to Memel or Riga timber in stiffness only.

Grove End, March 16, 1818.

I am, Sir, yours, &c.

THOMAS TREDGOLD.

*These experiments were made in the presence of His Grace the Duke of Atholl, Lord Prudhoe, Lord James Murray, John Deas Thomson, Esq., William Adair, Esq., Mr. Geo. Bullock, and Mr. Atkinson, architect to the Ordnance.

INDEX.

ACACIA, i. 39. By whom introduced, 42. Use of the timber,

44. Where to be planted, 45.
Age, old, the emblem of, i. 259.
Alder, i. 60. Its ancient use, 61.
65. Use of the timber, 64. 66.

How propagated, 68.

How propagated, 47.

Where to be planted, 63.
Medicinal properties, 67.

Alexander the Great, anecdote of, ii. 262.

America, the importance of the discovery, ii. 64. Its effect on

the system of botany, i. 41.

Amiability, the emblem of, i. 309.

Apollo's temple by whom robbed, i. 110.

Arbor vitæ, i. 51. Great quantity at Père la Chaise, 54. Use
of the wood, 56. Medicinal properties, 57. How propa-
gated, 58.

Arbutus, i. 69. Its ancient name, 70. Its flowers adapted to
the season, 73. Soil, 74. How propagated, 75. 77.

Archers, ancient, ii. 279.

Ash, i. 79. Fabulous account of, 80. Used for spears, ib.
Serpents will not approach it, 82. Superstition respecting
the ash, 83. Situation, 84. Profit of the wood, 86. Of
great size, 89. Used for fodder, 91. How propagated,

95.

weeping, i. 95.

manna, i. 96.

Aspen, i. 102. Its tremulous nature accounted for, ib.

Superstition respecting, 103. Use of the timber, 104.
Atholl, the Duke of, his plantation of larch, ii. 17.

Bachelor, the origin of the name of, i. 114.

Bay, i. 106. Why named laurus, 107. Superstition respect-
ing, 108. Thought to purify the air, ib. Why named
nobilis, 113. Used to crown poets, 114. Its early use in
England, 116.

tree at Virgil's tomb, 117. Situation, 118. How pro-
pagated, 121.

Beauty, the emblem of, ii. 149.

Birch, i. 123.

Origin of the name, 124. Natural climate,
125. Ancient use of the bark, 126. Reflections caused by
this tree, 128. Situation and use of the timber, 131.

wine, 130.

Bird cherry, i. 134.

Bladder senna, i. 138.

Use of the fruit, 136.

Good to fatten sheep, 140. Medicinal

quality, ib. Native soil, 141.

Bond of love, the emblem of, i. 294.

Botany, the pleasure of this study, i.

72. 271.

Box-tree, i. 144. Native soil, 145. Use of the wood, 146.
Used to colour hair, 148. Soil and situation, 150.

Broom, i. 151. Situation, 153. Uses of, 156. Medicinal
properties, 159. Use in veneering, 160.

Butcher's broom, ii. 309.

311.

Cassine, evergreen, i. 291.

Natural history of, 310. Qualities,

Cedar of Lebanon, i. 162. Planted by the Jews, 164. An-
tiquity of its use, 165. Durability of, 167.
Used to pre-
serve writings, ib. Character of, 168. When introduced,
169. Remaining at Libanus, 172. Natural history of, 175.
Thought to purify the air, and inspire religious thoughts, 176.
Soil and situation, ib.

Chaste love, the emblem of, i. 41.

Churches, why decorated with holly at Christmas, i. 281.
Clematis.

See Virgin's Bower.

Clipping of trees, by whom introduced, i. 302.

Cornel, i. 179.

-, by whom ridiculed, i. 304.

Ancient and modern use of, 182. 184. Si-

tuation, 185.

Cornelian cherry, i. 185. The fruit described, 187.

Coquetry, the emblem of, ii. 75.

Cypress, i. 188. Fabulous account of, 189. Why planted by
the Turks, 190. Singular use of a cypress-tree, 191.
Native soil and durability, 192. Ancient use in building
ships, 194. Where first noticed in England, 196. Where
to be planted, 199. 201. How propagated, 203.
Danger, the emblem of, ii. 207.

Daphnephoria, origin of the festival, i. 111.

Darius, anecdote of, i. 227.

Diana, the origin of her temple, i. 229.

Dogwood, i. 179.

Edda of Woden, allegory from, i. 81.

Eglantine, ii. 169.

Elegance, the emblem of, i. 48.

Elm, i. 205. Thought not to be a native, 207.

Ancient use
of, 209. Why planted in the church-yards of France, 211.
Forms the principal boulevards of France and Spain, 211.
Great size of, 213. 216. When planted in St. James's Park,
215. Beauty of, 216. Varieties of, 219. Use of the tim-

ber, 220.

Evaporation of leaves, i. 98.

Evergreens, remarks on planting, i. 198.

Fashion, her influence in planting, ii. 53.

Fir, i. 225. Natural history of, 226. To whom dedicated,
228. 231. Native soil, 233. Why named fir, 234. Not to
be pruned, 236. Situation, 237. Use of the timber, ib.
Good for fodder, 239.

silver, i. 241.

hemlock, i. 246.

balm of Gilead, i. 245.

- spruce, ii. 211.

Flowers, how doubled, i. 258.

the delight of all ages, i. 10. Banish grief, 9.

the drawing of, recommended as the proper study for

females, i. 11.

Forsaken, the, the emblem of, ii. 44.

Foresight, the emblem of, i. 280.

Friendship, the emblem of, i. 326.