71 



few months the links, or the keys of the shackles attaching the chain 

 to the bridle, become so much oxidated as to lose the requisite tenacity. 



The link, presented as a sample of the chain, is irregularly oxida- 

 ted and worn, presenting semi-spheroidal cavities, and the fibrous 

 structure of the iron is very distinctly developed. While this is the 

 case with the wrought iron part of the link, the cast iron stud which 

 strengthens it is not materially acted on. The raised letters upon the 

 stud are perfect. 



The circumstances in which this chain is differently situated from 

 others, used in similar situations, result from the peculiar construction 

 of the Light-boat, by which the copper sheathing rises above, and is 

 in contact with, the cast-iron hawse-pipe, through which the cable 

 passes. This cast-iron pipe has on its exterior a lead pipe. The 

 copper sheathing is bright. 



This action being attributed by Lieutenant Bache, to the contact 

 of the copper and iron in presence of sea-water, he had ordered the 

 copper to be removed from around the hawse-hole, the result of which 

 experiment would test the truth of the supposition. 



Professor Bache stated his wish to call special attention to the en- 

 tire soundness of the cast-iron, while the wrought-iron was corroded ; 

 as if the latter had acted as a protector to the former. He believed 

 that some general laws of interest would be made out by the Com- 

 mittee of the British Association engaged in investigating the subject 

 to which this fact appeared to belong. 



The Committee on making and collecting observations of 

 Celestial Phenomena, reported in part, that they had received 

 the following observations of Lunar Occultations of the fixed 

 stars, in mean time of the places of observation. 





1838. 





h m s 









1. 



No\ 



.2, 



d Pleiadum, Era. 



13 53 11.10 d. 1. 



Phila. Obs'y, 



w. 



and K 



2. 







h Im. 



13 18 12.10 b. 1. 



!) 





a 



3. 







Em. 



14 34 50.60 d. 1. 



;j 





)> 



4. 







/ Im. 



14 9 53.60 b. 1. 



)) 





v> 



5. 







Em. 



15 19 25.10 d. 1. 



!) 





3) 



6. 







h Em. 



15 26 34.40 d. 1. 



J) 





J) 



7. 



;? 



2] 



58 a> Sagittarii, Im. 



6 1 24.30 d. 1. 



)! 





)> 



8. 







„ Em. 



7 13 20 00 b. 1. 



;> 





;> 



9. 







* 8th mag. „ Im. 



6 9 12.30 d. 1. 



» 





)) 



10. 







60 a. Sagittarii, Im. 



7 43 5.10 d. 1. 



>; 



J. 



and K 



11. 



Dec. 



27, 



« Pleiadum, Im. 



8 34.70 d. 1. 



;j 



R. and W 



12. 







Em. 



9 17 33.80 b. 1. 



>) 





>•? 



