Intelligence and Miscellaneous Articles. 



305 



I have carefully analysed the mineral (when freed from pyrites), 

 and find its composition to be as under : 



Specific 

 gravity. 



Sul. Barytes 

 per cent. 



Carb. Lime 

 per cent. 



4-19 

 4-23 

 4-365 

 4-63 



88 



91-25 

 97 

 100 



12 



8-75 

 3 



As I am not aware of any notice of barytes having been found in 

 the coal-measures before, it perhaps may present some novelty to 

 your readers : otherwise I shall feel obliged by some of your corre- 

 spondents, better acquainted with the subject than myself, communi- 

 cating through the medium of your valuable journal any information 

 connected with the geological relations of this mineral. 

 I am, Gentlemen, yours respectfully, 



Henry Hough Watson. 



Little Bolton, Lancashire, Sept. 10, 1830. 



LAW OF PATENT INVENTIONS. 



Extracts from the Evidence taken before the Select Committee of the 

 House of Commons, on the Law relative to Patents for Inventions, 

 1829 ; being the Statement made by Mr. Farey respecting Mr. Woolfs 

 and Mr. Watt's Patents for Steam-engines; with Additional Facts 

 in Support of that Statement. 



[Continued from vol. vii. p. 157.] 



(P. 32 of the Report.) Do you consider that the term of fourteen 

 years is sufficient in all cases? — By no means. In the case of Mr. 

 Woolfs invention of working steam-engines by high-pressure steam 

 acting expansively, (either in one or in two cylinders,) there was no 

 profitable exercise of that invention for at least ten years out of the four- 

 teen ; and there was so much loss incurred at the first, that the profit 

 made during the last four years did not repay the loss during the first 

 period. (P. 33.) The extension since given to that invention is so im- 

 portant, that the existence of deep mining in Cornwall at this moment 

 depends upon it. The difference in cost between the quantity of coals 

 consumed by the engines now in use (which are all on Mr. Woolfs 

 system), and by an equal force of engines such as were in use before he 

 went into Cornwall in 1813, would absorb the profit of all the deep 

 mining that is now carried on in Cornwall. I think Mr. Woolf is 

 more entitled to a public reward for the services he has rendered, 

 without any recompence, than any inventor who has ever been re- 

 warded by Parliament. 



(P. 136.) It would be a very good measure to reserve a portion of 

 the revenue derived from the granting of patents, to accumulate and 

 form a fund for the purchase of valuable secret inventions, like Mrs. 



N.S. Vol. 8. No. 4-6. Oct. 1830. 2 R Knight's, 



