470 Scientific Intelligence. [June, 



oblate spheroid, does a fluid body, turning round a centre, out of 

 itself, assume the form of an oblong spheroid, gravity and projectile 

 force being the sufficient and obvious cause of each. And the 

 rotation of such body, upon any other than its longer axis, must, 

 as it presents a new part towards the centre round which it revolves, 

 constantly occasion two opposite tides. 



It is the necessary consequence of these laws, that there should 

 exist on our earth one lunar and one antilunar, one solar and one 

 antisolar tide. I am. Sir, with much respect. 



Your most obedient Servant, 



Newcastle, April 2d, 1814. ■\Y'^ 



IV, Prize Essay of the Royal Medical Society of Edinlurgh. 



The Royal Medical Society propose as the subject of their Prize 

 Essay for the year 1815, the following question : — 

 " The comparative specific caloric of venous and arterial blood." 



A set of books, or a medal of five guineas value, shall be given 

 annually to the author of the best disseitation on an experimental 

 subject proposed by the Society 5 for which all the members, 

 honorary, extraordinary, and ordinary, shall alone be invited as 

 candidates. 



The dissertations are to be written in English, French, or Latin, 

 and to be delivered to the Secretary on or before the first of De- 

 cember of the succeeding year to that in which the subjects are 

 proposed ; and t!ie adjudication of the prize shall take place in the 

 last week of February following. 



To each dissertation shall be prefixed a motto, and this motto is 

 to be written on the outside of a sealed packet, containing the 

 name and address of the author. No dissertation will be received 

 with the author's name affixed ; and all dissertations, except the 

 successful one, will be returned, if desired, with the sealed packet 

 unopened. 



V. On the Method of preserving Ships. 



The following valuable hints on this subject, so interesting at 

 present, are too important to require any introductory observations 

 from me. 



(To Dr. Thomson.) 

 MY DEAR Sin, Hackney Wick, ITth May, 1814. 



As peace has taken place, I beg leave to submit for consideration, 

 a method of preserving such of cur men of war as are building, 

 and also those which are finished and may now remain on the slips. 

 To aceomphsh this desirable purpose, a permanent roof should be 

 built over each vessel, which would serve for after vessels, with 

 gutters to carry oft^ the rain ; most of the treenails should be driven 

 out, leaving no more than are sufficient to confine the planks to 

 the timbers : the auger holes being left open will cause a continual 

 current of air, not only through the body of the vessel, but even 

 through the heart of the timber. I have good reason to believe 

 this would not only prevent the dry rot, but season the timbers, and 

 thus preserve the external and internal planks and increase the 



