346 On Mr. Donovan's Museum. 



spelter', but the former name is retained among the leamdd : 

 it was known to the Romans, who used it chiefly as an al- 

 loy, in which way it has been always found to possess very 

 singular properties. 



The expense of it as a covering is comparatively small, as, 

 in the experiment above alluded to, after every care had been 

 taken to lay it properly, the whole charge (including the altera- 

 tion of the rolls) did not exceed one shilling and threepence per 

 superficial foot, and it may be presumed that this was dearer 

 than it would be when practice has given facility to the exe- 

 cution. From this it appears that it is almost as cheap as 

 any covering, which promises durability, and not more than 

 one-third the price of lead. The architect may also avail 

 himself of its lightness to ceconomize in the construction 

 of his works. 



LV. Letter from Mr. Parkinson, of Hoxton- Square, 

 relative to Mr. Donovan's Museum. 



To Mr. Tilloch. 



PSIR, 

 ERMiT me, through your excellent publication, to ac- 

 knowledge my obligations to Mr. Donovan for the advan- 

 tages I have derived in my inquiries respecting the mineral- 

 ized remains of the animals of the former world, from the 

 examination of the inestimable fossils contained in his match- 

 less museum. 



By the investigations which I had previously made, and 

 from specimens in my own collection, I had ascertained 

 that England alone yielded several species of encrinities, as 

 I trust I shall show in the second volume of " Organic 

 Remains of the former World," now in the press. But by 

 an examination of the series of fossils in this department of 

 the London Museum, as above mentioned, I have gained 

 the knowledge that our own country can boast of yielding 

 at least one additional curious species of this animal hitherto, 

 I believe, unknown, and forming by the length of the arms 

 1 an 



