The Philosophical Instruments in the Paris Exhibition. 433 



vented another, of a more complicated kind. But although 

 several extremely ingenious calculating machines have been 

 constructed since that period, the only machine of the kind in 

 Paris was that exhibited by 0. Thomas, of Colinar, which 

 multiplies 8 figures by 8 in eighteen seconds; divides 16 

 figures by 8 in twenty-four seconds ; and extracts the square 

 root of 16 figures in ninety seconds. The price of this 

 machine was £20. It is to be regretted that a specimen of 

 the extremely beautiful calculating machine invented by the 

 Messrs. Scheutz, of Stockholm, was not exhibited. One of 

 these machines is employed in calculating a new life table in 

 the Registrar General's office in London, and simultaneously 

 prints the results. 



It would greatly exceed our limits to even briefly notice 

 the numerous objects falling under the head of miscellaneous 

 philosophical instruments. A few, however, are too important 

 to be omitted. Among them may be classed Lissajous' and 

 Desahr's apparatus for representing acoustic vibrations opti- 

 cally and graphically, exhibited by the maker, M. Keenig. 

 This apparatus is the most perfect that has been devised for 

 demonstrating the various combinations of rapid vibratory move- 

 ments. Many other beautiful and novel acoustical instruments 

 were exhibited by M. Koenig, who has been for many years 

 engaged with great success in investigating the laws of sound. 



The collection of spectacles by continental makers was 

 extremely large ; but as the eminent British makers of these 

 useful articles did not exhibit, no comparison can be instituted 

 between them and the former. How much machinery has 

 done to reduce the price of spectacles is apparent by the fact 

 that the house of Morey, Baillet, and Co. manufacture excellent 

 spectacles, in good steel frames, which are sold at 2s. 6d. the 

 dozen pair. In nearly all the spectacles exhibited provision 

 has been made to enable the axis of each eye to coincide with the 

 central spot of the lens, without which arrangement spectacles 

 must be always defective. 



In the department of philosophical instruments, the Paris 

 Exhibition contained a great variety of models of machines, 

 drawings for teaching the physical, natural, and musical 

 sciences, anatomical preparations, etc. With scarcely an ex- 

 ception, all these were contributed by continental countries, 

 the governments of which are far more disposed to afford 

 facilities for technological instruction than that of our own. 

 The objects of this nature exhibited by France, Belgium, 

 Prussia, Italy, and Russia, were admirably adapted for the 

 above purpose. There was a very interesting exhibition in 

 the department of anatomy, by Dr. Brunetti, of Padua, who 

 has discovered a process by which, in thirty hours, he can 

 VOL. XII. — NO. vi. f * 



