Mr. E. Turrell's Menstruum for Biimg-in on Steel Plates. 42 1 



sent I shall retain the old generic name, adding for specific 

 distinction the well-known Homeric epithet Dolichocleirus, as 

 characterizing the most striking peculiarity of its osteoloo-y, 

 I am the rather induced to follow this course because I think it 

 very probable, from specimens which I have examined, that 

 species of Plesiosuunis with shorter necks exist in other strata. 

 I have already figured a column, belonging to an animal of 

 this genus, in which the proportions of the Plesiosmirus Doli- 

 chodeirus are inverted, the vertebrae of the neck being consi« 

 derably thinner than those of the body. Professor Buckland 

 has since obtained from Market Raisin, large fragments of the 

 skeleton of the species to which that vertebral column must 

 have belonged; its remains are common in the Kimmeridge 

 or Oaktree clay. From its enormous size I shall provisionally 

 indicate this species as Plesiosaurus giganteus, and I hope herer 

 after (in union with my fi'iend) to submit drawings and a de- 

 scription of those remains to the Society. 



With i-eference to the elucidation of all these questions, I 

 cannot but congratulate the scientific public that the discovery 

 of this animal has been made at the very moment when the 

 illustrious Cuvier is engaged in, and on the eve of publishino-, 

 his researches on the fossil ovipara: from him the subject will 

 derive all that lucid order which he never has yet failed to 

 introduce into the most obscure and intricate departments of 

 comparative anatomy. 



LXVI. Menstruum for Biting-in 071 Steel Plates. By Mr. 

 Edmund Turrell, of Clarendon-street, Sotnerstovan*. 



THHE demand that has taken place for engravings upon de- 

 -■■ carbonized steel plates, on account of their great dura- 

 bility when compared with copper plates, has caused many 

 eminent artists to employ their talents upon that peculiar pre- 

 paration of metal ; and many beautiful specimens of line-en- 

 graving have been produced, capable of yielding proofs or 

 prints to an extent unknown before the invention and applica- 

 tion of that peculiar preparation of steel, which was first, I be- 

 lieve, made known to the world by Mr. Perkins, who has made 

 use of it very extensively in his bank-note manufactory in the 

 United States of America, and n)ore recently in London. 



II" the execution of a fine engraving upon such prepared or 

 decarbonized steel had depended entirely upon the graving 

 tool, the principal difficulty that presents itself would be the 



• From the Transactions of tlic Society of Arts.— The large gold medal 

 was presented to Mr. Turrell for this communication. 



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