2V8 



creased by your macMnery; that of the material, you are enabled to 

 reduce to that of lead, by the decreased quantity of metal required for 

 tin pipe for the same, or even greater strength. 



I think we may congratulate ourselves upon having thus placed with- 

 in our reach, this, the perfection of service pipe ; and I cannot but hope 

 that, for their own sakes, our citizens will at once adopt its general use. 

 I am, gentlemen, respectfully, your obedient servant, 



A. W. CRAVEN, 



Chief Engineer, dtc. 



Table, shoioing the Comparative Cost of Medium Lead and Block 



Tin Pipes. 



Calibres in inches and parts, . . -^ f f 1 1^ 1^ 2 

 Lead Pipe, cost per foot in 



cents, 12 20 24 31 33 46 60 



Block Tin Pipe, cost per foot 



in cents, 18 24 26 32 42 48 84 



GEOLOGICAL REPpRT. 



Office of the Mich. State Agricultural Society, ) 

 Detroit, May 25th, 1854. j 



Bbla Hubbard, Esq. : 



Sir — The frequent enquiries at this office, for information respecting 

 the TopogTaphical, Geological, and Mineralogical features of Michigan, 

 as they relate to the Mining and Agricultiu-al operations of the State, 

 and deeming a very general diffusion of such information, of great im- 

 portance to our present and future welfare, and finding in your re- 

 ports for 1840 and 1841, as Assistant State Geologist, much rehable in- 

 formation of the character sought for, I think the transfer of those re- 

 ports to the pages of the " Transactions" of the Michigan State Agri- 

 cultural Society, will greatly enhance the interest and value of the 

 work. 



I have, therefore, decided to make such transfer, and if any correc- 

 tions, alterations, or additions, to these reports, suggest themselves to 

 you, whereby they would be rendered more valuable, I would thank 

 you to make them. 



