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Cast iron beams
BLAeXW,~LL On the Instincts o f Birds.
139
according to the reports received from those embarked in her. This vessel was built by Mr. Laird, of Liverpool for the purpose of navigating the shoal water of the river, and we underst~.nd that he has since constructed another for the interior navigation of Ireland. W e have no doubt that these vessels from their vast superiority over those of wend, and their durable quality, will speedily be numerously employed. [Nautical Magazine.
Cast Iron J3eams. In the early application of cast iron beams, it often happened timt a beam broke without any apparent reason; and it was ultimately discovered that slight vib~'ations, or constant slight shocks, had the eit~ct of breaking even heavy beams; this lead to the application of a soft material placed under the parts of the beam, wl~ere supported by masonry, which, acting as a damper to vibt'ation, prnved of great utility in preserving cast iron beams. The cast iron chairs which receive the rails for raih'oads, have been fl)und to break in a similar manner, and in some instances of late, a piece of felting, made ofox hair, and consequently indestructible, has been placed between the stone sleepers and the chairs, which has produced a most advantageous result.
[Rep. Pat. Inv. ¶ POPULAR SCIENCE. No. VII.
On the Instincts of Birds. By JOHN BLAOKWALL,Esq. F.L.S. [Continued from p. 72.]
T h e habits and manners of birds are sometimes so greatly modified by the exercise of the intellectual f:aculfies, that, in many cases it becomes extremely diflicuit, if' not impossible~ to determine what is due to their intlnence; but that no small portion of intelligence is exhibit. ed in the following instances will scarcely be denied. T h e white headed eagle, and several of tt~e gulls, which prey upon the finny inhabitants of the waters, fi'equently save themselves the trouble of fishing, by robbing their more expert and less powerful congeners of the fruits of" their industry, occasionally compelling the objects of their violence even to disgorge their undigested tbod. The pied and yelh)w wagtails run close to the legs and noses Of cattle which are grazing, m pursuit of the insects disturbed by them. The same motive also induces these and many other birds to follow the husbandman, when he is busy with the plouo_h or harrow; and the redbreast attends l.he gardener in b,s labours, and stezes the worms which he turns up with his spade. Mr. White states, ~ that the great titmous% in severe weathe,', fi'e•
* Natural llistory of Selborne, p. 106.
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139
according to the reports received from those embarked in her. This vessel was built by Mr. Laird, of Liverpool for the purpose of navigating the shoal water of the river, and we underst~.nd that he has since constructed another for the interior navigation of Ireland. W e have no doubt that these vessels from their vast superiority over those of wend, and their durable quality, will speedily be numerously employed. [Nautical Magazine.
Cast Iron J3eams. In the early application of cast iron beams, it often happened timt a beam broke without any apparent reason; and it was ultimately discovered that slight vib~'ations, or constant slight shocks, had the eit~ct of breaking even heavy beams; this lead to the application of a soft material placed under the parts of the beam, wl~ere supported by masonry, which, acting as a damper to vibt'ation, prnved of great utility in preserving cast iron beams. The cast iron chairs which receive the rails for raih'oads, have been fl)und to break in a similar manner, and in some instances of late, a piece of felting, made ofox hair, and consequently indestructible, has been placed between the stone sleepers and the chairs, which has produced a most advantageous result.
[Rep. Pat. Inv. ¶ POPULAR SCIENCE. No. VII.
On the Instincts of Birds. By JOHN BLAOKWALL,Esq. F.L.S. [Continued from p. 72.]
T h e habits and manners of birds are sometimes so greatly modified by the exercise of the intellectual f:aculfies, that, in many cases it becomes extremely diflicuit, if' not impossible~ to determine what is due to their intlnence; but that no small portion of intelligence is exhibit. ed in the following instances will scarcely be denied. T h e white headed eagle, and several of tt~e gulls, which prey upon the finny inhabitants of the waters, fi'equently save themselves the trouble of fishing, by robbing their more expert and less powerful congeners of the fruits of" their industry, occasionally compelling the objects of their violence even to disgorge their undigested tbod. The pied and yelh)w wagtails run close to the legs and noses Of cattle which are grazing, m pursuit of the insects disturbed by them. The same motive also induces these and many other birds to follow the husbandman, when he is busy with the plouo_h or harrow; and the redbreast attends l.he gardener in b,s labours, and stezes the worms which he turns up with his spade. Mr. White states, ~ that the great titmous% in severe weathe,', fi'e•
* Natural llistory of Selborne, p. 106.
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