NEW PHILOSOPHICAL INSTRUMENTS, 



MADE BY 



ANDREW PRITCHARD, 



162, FLJEET STREET, LONDON. 



PRITCHARD'S POCKET MICROSCOPE. 



THIS Instrument is very steady, its construction simple, and not liable to derange- 

 ment. It is furnished with rack-adjustment, concave mirror, and four magnifiers. 

 Price, in case, 38*. 



PRITCHARD'S GARDEN-FRAME THERMOMETER 



Is inclosed in a strong glass case, mounted with brass, so that it can be inserted into 

 the earth without danger. It will be found of great value for Mushroom beds, and 

 the striking of delicate Flower Plants in frames. It is so graduated, that any person 

 may, by mere inspection, know whether the heat is too great or too little, and thus 

 prevent injury to the plants. Price 18*. to 28*. 



PRITCHARD'S THERMO-HYGROMETER. 



This elegant little instrument indicates temperature, dryness, and humidity. It 

 will be found peculiarly useful in winter, especially in the apartments and chamber of 

 the Invalid, as it enables him to regulate with facility the proper state of dryness. In 

 rooms heated by closed stoves, air, or water, it should always be present. Price, on 

 ebony pedestal, 21*. 



PRITCHARD'S GEOLOGICAL SLIDES. 



This set of Slides illustrate, with the Phantasmagoria, or Magic Lanthorn, the 

 principles of Geology, exhibiting the various strata of the earth and their relative 

 positions. Also, the different Vegetables and Animals living and extant, peculiar to 

 each deposit. They will be found peculiarly useful for public and private instruction. 

 Price 3 15*. per set. 



In tfjc 



(Price to Subscribers, 24s. ; to Non-Subscribers, 30s.) 



A HISTORY OF INFUSORIA; 



LIVING AND FOSSIL; 



ARRANGED ACCORDING TO THE 



DIE INFUSIONSTHIERCHEN OF C. G. EHRENBERG. 



ILLUSTRATED BY 



SEVERAL HUNDRED ACCURATE COLOURED ENGRAVINGS OF THESE CURIOUS 

 CREATURES, HIGHLY MAGNIFIED. 



BY ANDREW PRITCHARD, 



Author of the "Microscopic Illustrations," "Natural History of Animalcules," &c. 



This Work will contain descriptions of the external characters, internal structure, 

 instincts, habits, and locomotion of these interesting living atoms, forming a complete 

 Manual on this subject ; and it is believed will become of deep interest, not only to the 

 physiologist, microscopic and general observer, but also to the Botanist, as contain- 

 ing accurate figures of many creatures hitherto considered as belonging to the vege- 

 table kingdom. 



Subscribers' names received at 162, Fleet-street, London. 



J. Uarkio, Printer, 3, Cloude^ley -street, Islington. 



