234< Royal Society. 



proportion only of carbonate of lime. This vessel had been em- 

 ployed previously in transatlantic voyages, and also in intercolonial 

 ones, plying between Bermudas and the Island of St. Thomas, and 

 in the Caribbean sea and the Gulf of Mexico. 



The composition of this incrustation, like the preceding results, 

 ^ould seem to denote, if any satisfactory inference may be drawn 

 from it, that carbonate of lime is in small proportion in deep water 

 distant from land, and that sulphate of lime is commonly more 

 abundant. The results of a few trials I have made, whilst rather 

 confirmatory of this conclusion, showed marked differences as to the 

 proportion of sulphate of lime in sea-water in different situations. 

 That from Carlisle Bay was found to contain 11*3 per 10,000. A 

 specimen taken up in lat. 29° 19' and long. 50° 45', yielded about 

 2 per 10,000, with a trace of carbonate of lime. A specimen taken 

 up off Fayal yielded about 9 per 10,000, also with a trace of car- 

 bonate of lime. One taken up off Portland Head, about fifteen miles 

 distant, yielded, as already remarked, only "^ per 10,00*0, part of 

 which was sulphate, part carbonate of lime. 



By certain management, I am informed, as by not allowing the 

 sea-water in the boilers to be concentrated beyond a certain degree, 

 the incrustation, in the instances of the transatlantic steamers, is in a 

 great measure prevented. Perhaps it might be prevented altogether, 

 were sea- water never used but with this precaution, and taken up at 

 a good distance from land, and in situations where it is known that 

 the proportion of sulphate of lime is small. If this suggestion be of 

 any worth, further, more extensive and exact inquiry will be re- 

 quisite to determine the proportion of sulphate of lime in different 

 parts of the ocean, and more especially towards land. By the aid of 

 the transatlantic steam navigation companies means for such an in- 

 quiry may easily be obtained ; and it can hardly be doubted that 

 the results will amply repay any cost or trouble incurred. 



Lesketh How, Ambleside, 

 March 29, 1849. 



" On the Universal Law of Attraction, including that of Gra- 

 vitation, as a particular case of approximation deducible from the 

 principle that equal and similar particles of matter move similarly 

 relatively to each other." By John Kinnersley Smythies, Esq. Com- 

 municated by T. F. Ellis, Esq., F.R.S. 



After stating the general object of his investigations and explain- 

 ing the notation he employs, the author enters upon some prelimi- 

 nary geometrical inquiries. He gives the equation between the six 

 right lines drawn between four points in a plane ; the solidity of a 

 tetrahedron in terms of its edges : the equation between the cosines 

 of the six angles made by four right lines meeting in a point ; and 

 the equation between ten right lines drawn between five points, with 

 some formulee of verification. Giving some general rules for the 

 transformation and consolidation of series, he transforms the last 

 equation into one involving the solidities of tetrahedrons, and shows 

 how the sign of each tetrahedron in that equation is determined by 



