S28 Mr Hardie's Outline of the 



the tube required by the foriner. The inconveniences of PloessePs 

 microscope are, — its almost entire uselessness for the observation 

 of fluids, on account of the small distance of the object-lens 

 from the object under the high powers, and the impossibility of 

 employing apparatus for pressure, not even mica. It is also, 

 on account of its varied adjustments, and particularly a very 

 fine screw-micrometer, twice the price of Chevalier's ; therefore 

 only half as useful considered in the abstract. Its form is much 

 handsomer than that of Chevalier, and more convenient for use. 



Schiek's microscope unites the advantages of both of the 

 others. Its field of vision is extensive, extremely sharp and 

 clear illumination, even to the highest powers, appearing to me 

 much clearer than either of the others when I compared them 

 together. Its magnifying powers equal the highest of PloessePs, 

 therefore twice that of Chevalier's, accompanied with consider- 

 able focal distance, permitting of the use of water and pressure 

 for the most minute objects. Its size is smaller, and form more 

 convenient and handsomer than the others without being weaker. 

 From the simplicity of its arrangements, the price is very mo- 

 derate, and therefore particularly adapted for the working na- 

 turalist. 



The greater clearness of the image, and sufficiency of light, 

 ^s a step made by M. Schick which is a clear gain to optics ; 

 which, united to all the other advantages, have appeared to me 

 quite new and surprising. 



Outline of the Geology of the Bhurtpoor District. By James 

 Hardie, Esq. Bengal Medical Estabhshment. Communi- 

 cated by the Author. 



This district may be described as forming a portion of the 

 south-western boundary of the Valley of the Ganges and Jumna. 

 It presents a level platform, elevated about sixty feet above the 

 bed of the latter river, and is in most situations covered with 

 the usual alluvium of the Gangetic provinces. The country 

 is fertile and highly cultivated, and impresses us with a favour- 

 able idea of the industry and enterprise of the Jauts, as con- 

 trasted with their Rajpoot neighbours of Jeypoor. The lesson 



