GENTLE READER, I 



The volume of "CURIOSITIES" which I here present to your 

 notice is a portion of the result of a long course of reading, obser- 

 vation, and research, necessary for the compilation of thirty volumes 

 of "Arcana of Science" and "Year -Book of Facts," published 

 from 1828 to 1858. Throughout this period nearly half of the 

 Psalmist's "days of our years" I have been blessed with health 

 and strength to produce these volumes, year by year (with one 

 exception), upon the appointed day; and this with unbroken at- 

 tention to periodical duties, frequently rendered harassing or 

 ungenial. Nevertheless, during these three decades I have found 

 my account in the increasing approbation of the reading public, 

 which has been so largely extended to the series of " THINGS NOT 

 GENERALLY KNOWN," of which the present volume of" CURIOSITIES 

 OF SCIENCE" is an instalment. I need scarcely add, that in its pro- 

 gressive preparation I have endeavoured to compare, weigh, and 

 consider, the contents, so as to combine the experience of the Past 

 with the advantages of the Present. 



In these days of universal attainments, when Science becomes 

 not merely a luxury to the rich, but bread to the poor, and when 

 the very amusements as well as the conveniences of life have taken 

 a scientific colour, it is reasonable to hope that the present volume 

 may be acceptable to a large class of seekers after " things not 

 generally known." For this purpose, I have aimed at soundness as 

 well as popularity; although, for myself, I can claim little beyond 

 being one of those industrious " ants of science" who garner facts, 

 and by selection and comparison adapt them for a wider circle of 

 readers than they were originally expected to reach. In each case, 

 as far as possible, these "CURIOSITIES" bear the mint-mark of au- 

 thority; and in the living list are prominent the names of Humboldt 

 and Herschel, Airy and Whewell, Faraday, Brewster, Owen, and 

 Agassiz, Maury, Wheatstone, and Hunt, from whose writings and 

 researches the following pages are frequently enriched. 



The sciences here illustrated are, in the main, Astronomy and 

 Meteorology ; Geology and Paleontology ; Physical Geography ; 

 Sound, Light, and Heat; Magnetism and Electricity, the latter 

 with special attention to the great marvel of our times, the Elec- 

 tro-magnetic Telegraph. I hope, at no very distant period, to ex- 

 tend the " CURIOSITIES" to another volume, to include branches of 

 Natural and Experimental Science which are not here presented. 



I. T. 



November 1858. 



M35S761 



