352 



Varieties. 



[MARCH, 



Naval Force in France. The naval 

 force in France consisted, on the first of 

 January, 1829, of 276 ships of the line, of 

 various ranks: viz 33 men-of-war, 41 

 frigates, C corvettes, 25 brigs of sixteen to 

 twenty guns each, 8 tenders carrying eigh- 

 teen guns, 15 brigs of sixteen guns, and 151 

 vessels of other calibre. The number of 

 vessels building is 80. The various sta- 

 tions will require for the present year, 1830, 

 should no extraordinary event happen, 128 

 ships of war : viz. 1 line of battle ship, 

 14 frigates, 79 other vessels of less calibre, 

 27 transports, and 7 steam vessels. The 

 following is the comparative pay of the 

 naval officers of the various powers, not in- 

 cluding mess allowances : 



Francs. 

 An English Vice Admiral . . . 36,000 



A Dutch ditto 38,700 



A French ditto 28,000 



An English Rear Admiral . . 27,000 



A Dutch ditto 24,250 



A French ditto 12,000 



An English Commander .... 12,911 



A Dutch ditto 17,200 



A Russian ditto 10,920 



A United States Commander 7? 120 



A French ditto 6,000 



An English Commander of a 



Frigate 7,475 



A Dutch ditto 6,450 



A Russian ditto 4,740 



A United States ditto 4,212 



A French ditto 4,200 



On the Impressions produced by Light 

 on the Eye The following are the con- 

 clusions to an essay on this subject by M. 

 Plateau. 1. I. Any sensation of light what- 

 ever requires an appreciable time for its 

 complete formation, and also the same time 

 for its complete disappearance. II. The 

 sensations do not disappear suddenly but 

 gradually diminish in intensity. III. As 

 a sensation fades the progress of its decrease 

 is slower as the effect is nearer to a close. 

 IV. Different colours, illuminated by day- 

 light, produce sensations differing little 

 from each other in their total duration. 

 The order of them in this respect begin- 

 ning with that which produces the longest 

 sensation is white, yellow, red, blue. V. 

 The total duration, from the tisne when 

 the sensation has acquired its greatest 

 power, to that when it is hardly sensible, is 

 very nearly 0-34 of a second. VI. Finally, 

 it results accidentally from the experiments 

 that the principal colours arranged accord- 

 ing to the intensity of sensations which 

 they are competent to produce, stand in the 

 following order white, yellow, red, blue. 



2. I. New proofs confirm the order of 

 colours contained in the sixth result of the 

 first section. II. The visual angles, under 

 which M. Plateau can see the different 

 colours are as follows. 



In the Shade. In Sun Light. 



White 18". 12". 



Yellow 19" 13". 



Red 31" 23". 



Blue 42" 26". 



The angles observed in sun light are nearly 

 a third of those in the shade. III. When 

 the sensations of two different colours suc- 

 ceed each other on the retina with a velo- 

 city less than that necessary to make the 

 two impressions appear as one, there gene- 

 rally appear certain shades v/hich are ex- 

 traneous to the two colours employed or to 

 their mixture ; by these means a fine white 

 can be obtained when the yellow and blue 

 colours only are used. IV. When two 

 alternating sensations succeed each other 

 with such rapidity that they produce but 

 one impression, the latter does not always 

 present a colour which would result from 

 the mixture of the former, thus combining 

 the effect of yellow with that of deep blue 

 in the way just mentioned, a grey colour 

 can be produced without the least appear- 

 ance of green. V. With the exception 

 perhaps of yellow, the sensations of certain 

 colours do not act in their combination 

 with other sensations in the order of the in- 

 tensity of their colours : their maximum of 

 influence exists in a certain pale tint, on 

 each side of which their influence dimi- 

 nishes ; thus the blue colour of maximum 

 power with respect to red and yellow is that 

 of the sky in its most coloured state. 



Fossil Bones. At Argant, near Vin- 

 gran, in the department of the Eastern 

 Pyrenees, a cavern has been discovered, con- 

 taining the fossil bones of various animals, 

 rhinoceri, horses, oxen, sheep, deer, and 

 some extinct ; others of species still exist- 

 ing ; but what is most remarkable, there are 

 not among them the bones of any carnive- 

 rous animals. 



Improved Pianoforte Hammer An 

 American has improved the hammer heads 

 of pianofortes by letting into the top of 

 them a piece of lead, pewter, solder, zinc, 

 tin, iron composition of metals, or com- 

 pound of metals; and the hammer heads 

 having one of these kinds or compositions of 

 metals inserted in the tops of them, and 

 then covered with leather, or any other 

 covering, produces, when struck against the 

 strings, a much stronger, fuller, and firmer 

 tone than that produced by the common 

 sort of hammers. 



