Intelligence and Miscellaneous Articles, J 59 



'O 



esteem him much. I studied at Brunswick under Knoch, and here 

 at Gottingen under Blumenbach. Already in 1803, and therefore 

 earlier than Mohs, I became a mineralogical writer, building my 

 system on peculiar views belonging to no other school. I was the 

 first who appeared as opponent to Werner; assisted in the spreading 

 of Hauy's theory ; and published my first mineralogical system 

 in 1809^ founded on chemical composition and external characters. 

 I gave in 1813 a complete Handbuch on Mineralogy. Later I 

 treated Crystallography on a method of my own, totally different 

 from that of Mohs, though he was publishing at the same time; and 

 in 1821 I completed my method in a quarto volume of 677 pages, 

 entitled, 'Examinations on the Forms of Lifeless Nature;' and next, 

 in the first volume of my new edition of Mineralogy, in 1828, which 

 work I had the honour to present to the London Geological Society. 

 Had Mr. W. looked into this book, he might have convinced him- 

 self of his erroneous assertion; and as it is not indifferent to me 

 how England judges of me, I should be greatly obliged if through 

 your Journal his statement could be rectified. Hausmann." 



IMPROVEMENT IN PROFESSOR HENSLOW's CLINOMETER. BY 

 J. H. PRATT, ESQ. 



To the Editors of the Philosophical Magazine and Journal. 



Gentlemen, 

 I have lately had occasion to purchase one of the Clinometers 

 sold by Messrs. Watkins and Hill, Charing Cross, and invented, 

 I believe, by Professor Henslow ; but being struck with the want 

 of accuracy, or rather the liability of error, in the determination of 

 the dip of a stratum by its means, 1 have been induced to make a 

 slight alteration in the construction. My own I have had altered, 

 and find it answers very well, and the object of my troubling you 

 with this communication is to suggest the same to any person that 

 may have experienced the same inconvenience with myself. The 

 only alteration is to have the spirit-level on the outside of the lid 

 of the box, instead of the inside of the bottom of the box. With 

 this construction it is necessary merely to place the box flat on the 

 bed of the stratum and elevate the lid till the spirit-level shows that 

 the lid is horizontal : the brazen arc will then show the dip. 



1 remain, yours, &c. 

 Finsbury Circus, June 12, 1834. J. H. Pratt. 



P.S. The spirit-level is so imbedded in the wood that there is no 

 fear of its being broken. 



PRIMARY GEOLOGY. 



We are informed that Dr. Boase's Treatise on Primary Geology, 

 just published, contains, in addition to copious practical details 

 concerning the primary rocks, a full exposition of his objections to 

 the prevailing Plutonic Theory. This subject, it may be remem- 

 bered, was appointed by the British Association for the Advance- 

 ment of Science, at Cambridge, to be discussed at their next meeting 

 at Edinburgh. 



