Mechanical Science. 449 



ship, belonging to Colonel Perkins, which had been salted 

 when built fourteen years ago, required extensive repairs, and 

 a complete examination was made as to the state of the timbers, 

 they were found every where perfectly sound. A vessel of 

 500 tons required 500 bushels of salt, and after two years 

 100 bushels more to fill up the space left by salt dissolved 

 away. 



9. Preservation of Eggs. — It is proposed to preserve eggs 

 by covering them with a coat of gum arabic, rather than of var- 

 nish, and then to imbed them in charcoal. The gum is readily 

 removed by water, and the charcoal preserves the eggs from any 

 great and sudden change of temperature in passing from one 

 country or situation to another. 



10. Le Bateau Roulant. — Some trials of a boat, on a new 

 construction, are said to have lately been made at Paris. In 

 the second trial the inventor placed himself, with his apparatus, 

 below the platform of the Pont-Neuf. He set out from this 

 point at ten minutes before ten o'clock, having on board M. Da- 

 cheux, an experienced mariner, who took charge of the helm ; 

 Messrs. Marlet and Thibault, inspectors of the navigation, fol- 

 lowed in another boat to observe the operations. In twenty 

 minutes at the utmost he proceeded beyond the Pont Royal, 

 after having passed and re-passed under the arches, and landed 

 opposite the Quay d'Orsay. There he made his land apparatus 

 act, and roll the boat to the school of natation, which was tlie 

 end of his expedition. 



The inventor asserts that his machine will roll the boat on 

 the land, or navigate it in the water with equal ease, and that 

 neither motion is inteiTupted, or the velocity impeded. The 

 boat may go with the wind, or against it, and tack, ascend, and 

 descend a river at pleasure, and that with more rapidity than a 

 common boat. 



11. Whale- Torpedoes, — A vessel has recently been fitted at 

 New Bedford, in America, bound on a whaling voyage, with an 



