SUPERIORITY OF ELASTIC CABLES. 



127 



German silver, and produces scarcely any 

 galvanic action with a piece of zinc. The 

 above test is almost infallible, and recom- 

 mends itself from its simplicity. — National 



Intelligencer. 



SWIFTNESS OF BIRDS. 



The smallest bird, says M. Virey, can 

 fly several leagues in an hour ; the hawk 

 goes commonly at the rate of a league in 

 four minutes, or above forty miles in an 

 hour. A falcon of Heiiry Second was flown 

 from Fontainbleau, and found by its ring 

 at Malta the next day. One sent from 

 Canaries to Andalusia, returned to Tene- 

 riffe in sixteen hours ; a distance of near 

 seven hundred miles, which it must have 

 gone at the average rate of twenty-four 

 miles an hour. Gulls go seven hundred 

 miles to sea and return daily ; frigate birds 

 have been found at twelve hundred miles 

 from any land. Upon their migration, he 

 states as a known fact, that cranes go and 

 return at the same date, without the least 

 regard to the state of the weather, which 

 shows no doubt, if true, a most peculiar 

 instinct ; but these, and indeed, all facts 

 which we find stated by a writer so much 

 addicted to painting and colouring, must 

 be received with a degree of suspicion, 

 for which no one but M- Virey is to be 

 blamed. The accounts, however, of the 

 swiftness of birds, I can well credit, from 

 an experiment which I made when tra- 

 velling on a railway. While going at the 

 rate of thirty miles an hour, I let fly a 

 bee ; it made its circles as usual, and sur- 

 rounded us easily. Now if there was no 

 current of air or draft to bear it along, 

 this indicated a rate of ninety miles an 

 hour ; and even allowing for a current, 

 the swiftness must have been great. I 

 should, however, wish to repeat the expe- 

 riment before being quite sure of so great 

 a swiftness in so small an insect. 



again till they reach Pittsburg. These 

 cars are water-proof, and there is no 

 handling of goods, nor liability to damage 

 from the weather, or depredations while 

 on the route. Each car body will con- 

 tain about 6000 pounds of merchandize, 

 a train of which is despatched daily to 

 York by the rail-road. At York the car 

 body is transferred by simple machinery 

 from the rail-road to a platform road wa- 

 gon in three minutes, and is conveyed on 

 the turnpike to Columbia, where by simi- 

 lar machinery, it is transferred to the ca- 

 nal boat, and despatched without delay to 

 Pittsburg. Each canal boat carries ten 

 car bodies, or thirty tons of merchandize. 

 — Lord Broushani's Dissertation o?i Science. 



TRANSPORTATION OF GOODS BY RAIL-ROADS, 

 m'aDAMIZED ROADS, AND CANALS. 



The Baltimore American of April 9th, 

 states that goods are now transported 

 from that city by the way of York, 

 Wrightsville, and the Pennsylvania canal 

 and rail-road to Pittsburg. The trans- 

 portation of goods is done in portable car 

 bodies, which, after being packed in Bal- 

 timore, are locked up and not opened 



SUPERIORITY OF ELASTIC CABLES. 



Mr. Hennessey, the inventor of the 

 elastic life boat, has addressed a letter to 

 the editor of the Liverpool Mercury, in 

 which he shows the great superiority of 

 cables fabricated of elastic materials, over 

 those of a different character, especially 

 in riding out a heavy gale of wind. The 

 following is an extract from the letter: — 

 " Many years ago I was mate of a vessel 

 of 350 tons. We were lying in Gibralter 

 roads, with a thirteen inch hemp cable 

 and best bower anchor down ; the morn- 

 ing was fine, the master and chief part of 

 the crew went on shore for water, &c., 

 and before they were ready, it came on 

 to a blow so hard that they could not re- 

 turn to the ship. I had what seamen call 

 the long service out ; but as the gale was 

 still increasing, I gave cable to the end 

 clenched to the foremast. I had on board 

 a nine inch bass cable of 120 fathoms, 

 never wet, which I bent in place of a 

 hemp cable to the second bower. This 

 bass is a kind of grass, very cheap in Por- 

 tugal, called spartha, in the language of 

 that country. We run up the forestay- 

 sail, gave the ship a broad sheer, and let 

 go the grass cable under foot. The gale 

 increased to a tempest, — such as I never 

 saw before or since ; although in ballast 

 riding head to wind, and having a very 

 quick sheer abaft, we had to fix the dead 

 lights, or she would have filled through 

 the cabin windows, whilst riding by the 

 hemp cable. At twelve at night the bower 

 burst, the ship brought up by the grass 

 cable, and although the wind and sea in- 



