Transcriber Note Text emphasis is denoted as _Italics_ and =Bold=. Whole and fractional parts of numbers as 123-4/5. THOUGHTS ON A PEBBLE. [Illustration] REEVE, BENHAM, AND REEVE, PRINTERS AND PUBLISHERS OF SCIENTIFIC WORKS, KING WILLIAM STREET, STRAND. [Illustration: GIDEON ALGERNON MANTELL, L.L.D. F.R.S _Vice-President of the Geological Society &c. &c._] THOUGHTS ON A PEBBLE, OR, A FIRST LESSON IN GEOLOGY. BY THE AUTHOR OF "THE WONDERS OF GEOLOGY." [Illustration: _The Nautilus and the Ammonite._ _Vide_, p. 57.] "There is no picking up a pebble by the brook-side, without finding all nature in connexion with it." _Contemplations of Nature._ EIGHTH EDITION; WITH THIRTY-TWO ILLUSTRATIONS. LONDON: REEVE, BENHAM, AND REEVE, KING WILLIAM STREET, STRAND. 1849. TO MY SON, =Reginald Nebille Mantell, C.E.,= THESE "THOUGHTS ON A PEBBLE" ARE MOST AFFECTIONATELY INSCRIBED. LONDON, 19, CHESTER SQUARE, PIMLICO. 1849. "Every grain of sand is an immensity--every leaf a world--every insect an assemblage of incomprehensible effects in which reflection is lost." Lavater. "To the natural philosopher there is no natural object that is unimportant or trifling. From the least of Nature's works he may learn the greatest lessons. The fall of an apple to the ground may raise his thoughts to the laws which govern the revolutions of the planets in their orbits; or the situation of a _pebble_ may afford him evidence of the state of the globe he inhabits, myriads of ages before his species became its denizens." Sir J. F. W. Herschel. TO THE READER. Deeply impressed with the conviction that it is of the highest importance the young and inquiring mind should have a correct idea of natural phenomena--that it should not be left to its own unaided efforts to unravel the mysteries of the beautiful world in which this first state of being is destined to be passed--or have its curiosity stifled or misled by unsatisfactory or erroneous conjectures--I have endeavoured in this little work to explain in a simple and attractive guise, some of the grand truths relating to the ancient physical history of our planet, which modern geology has established.