468 Scientific Intelligence. [Dec. 



II. Improvement in Woulfe's Apparatus. 



The following improved form of Woulfe's apparatus is due to the 



Marquess Ridolfi. The bottles have three apertures as usual; and 



the middle one, intended for the purpose of cleansing the bottle, or 



the introduction of materials, is closed either by a cork or a stopper; 



tubes descend by the other two into the bottles, one a little way in, 



the other nearly to the bottom ; these tubes are small ; they are fastened 



into the neck of the bottle, and do not rise far above. Each of these 



is surrounded on the exterior of the bottle by a larger tube as high as 



themselves, and fastened by cement on the tops of the necks or tubu- 



lars, so as to form a little vessel to receive mercury round the outside 



of the smaller tube. The connexion is then easily made between one 



or more of these bottles by glass tubes bent twice at right angles, and 



of such size as easily to slip in between the two tubes before described. 



When the lower ends are immersed in the mercury, all is tight, and the 



apparatus maybe set to work. This contrivance allows a little motion 



to the bottles without endangering them ; they are instantly connected 



or unconnected at pleasure, and they act to a certain extent as tubes 



of safety. — (Journal of Science.) 



III. Yellow Fever. 



An English physician has lately published a letter against the pre- 

 cautionary measures adopted by the Spanish government to prevent 

 contagion. He observes, that the fears which these measures excite, 

 the want of care experienced by the sick who are abandoned, and the 

 famine which follows the suspension of all communication with a town, 

 are circumstances which extend the ravages of the fever to those who 

 would otherwise have resisted the contagion. He advises the cleaning 

 of the places where the disease prevails, and the allowing persons not 

 affected to remove to healthy districts. 



The following Prize Questions connected with this subject have lately 

 been proposed by the Academic Society of Nantes : 



" What are the origin, the causes, and the nature, of the yellow 

 fever ? " 



" What are the means of preventing it ? " 



IV. Ancient Boats. 



Two oak canoes of great antiquity have lately been discovered in 

 Loughisland Ravey, near Castlewellan, Ireland. They were each 21 

 feet in length, and excavated from the tree; the whole of the wood 

 being perfectly sound and in a high state of preservation. It appears 

 that they were intended, when lashed together, to form a double boat, 

 such as is now employed in the South Seas, the right side of the one, 

 and the left side of the other being convex in form, while the two oppo- 

 site sides were perfectly strait, so that they could very readily be joined 

 together. Unfortunately the finders of these primeval relicts in a few 

 hours destroyed what the lapse of ages had failed to effect. 



V. Steam Navigation. 



It is generally supposed that the application of the steam-engine to 

 the purposes of navigation is of very recent invention : this, however, 

 is not the case, as a patent was granted to Jonathan Hulls iu 1736, in 



