PROCEEDINGS OF SOCIETIES. 293 



nominal power of the object-glass ; this quite meets the case. In such 

 a difficult and complex arrangement as a high-power object-glass, it is 

 almost impossible for all the makers to work to the same magnifying 

 standard. From an early date, -^ths were ^ths or ^V*^^) ^^^ some now 

 approach to -^i^ths in power. There is almost the same discrepancy 

 as in the nominal and real horse-power of steam-engines, by makers 

 who vie with each other to give the best measure, and anyone that 

 now obtains a y^th for what was formerly an -^^th, may congratulate 

 himself in getting more for his money. 



Yours sincerely, 



F. H. Wenham. 



A MiNERALOGICAL MiCROSCOPE. 

 To the Editor of the ' Monthly Microscopical Journal.' 



New University Club, Nov. 8, 1871. 

 Sir, — Dr. Lawrence Smith contrived a form of microscope for 

 examining minerals, one of the features of which is that objects are 

 viewed from the lower side. My own pursuits are such as to require 

 this, but I can obtain no definite answer as to form and price of 

 instrument from those London microscope makers whom I have con- 

 sulted. 



I should be very glad if your readers, both here and in America, 

 would forward my chemico-mineralogical work by giving me any 

 information. Of coui'se it is an object to use such apparatus as I have, 

 which can be adapted to the new instrument. 



I would also ask whether this form of microscope might not be 

 made to take the place of the laboratory spectroscope. 



I am. Sir, your faithful servant, 



Marshall Hall. 



PEOCEEDINGS OF SOCIETIES.* 



EoYAL Microscopical Society. 



King's College, Nov. 1, 1871. 



W. Kitchen Parker, Esq., F.E.S., F.Z.S., in the chair. 



The minutes of the last meeting were read and confirmed. 



A list of donations was read, and a vote of thanks given to the 

 respective donors. 



The Secretary announced that he had received from Mr. Stanistreet, 

 for the Society, two beautiful specimens of his engraving, or Micro- 

 ruling, on glass. Also a photograph of his machine. There was an 

 engraving from the photograph which was rather more intelligible 



* Secretaries of Societies will greatly oblige us by writing their report legibly 

 — especially by printing the technical terms thus : H y dr a— and by "underlining" 

 words, such as specific names, which must be printed in italics. They will thus 

 secure accuracy and enhance the value of their proceedings. — Ed, ' M. M. J.' 



T 2 



