BISECTIONS FOE COLLECTING FOSSILS. 



473 



change of colour, lustre, texture, partial fusion or vitrifica- 

 tion, &c., and many of them may be illustrated by suites of 

 specimens carefully, and judiciously selected. 



13. An enumeration of the several instruments required* 

 by the geological traveller, for determining the direction and 

 inclination of the strata, for measuring heights, &c., as 

 likewise those for mineralogical investigation, would be 

 superfluous to the proficient in geology and mineralogy, and 

 of no avail to the less scientific collector, who, if he wish for 

 information, is necessarily referred to treatises on those 

 sciences. It is, however, otherwise as regards that indis- 

 pensable implement, the hammer. Two of these, at least, 

 are required ; one weighing from two to four pounds and a 

 half, for breaking the masses ; the other of smaller 

 dimensions, for trimming the specimens. Common hammers 

 are not fit for the purpose ; they should be of well-tempered 

 steel, the handles of very tough wood, and most firmly 

 inserted in the heads. The diagrams here given represent 

 those more commonly used, and which may be had of Messrs. 

 E. and Gr. Knight, Foster-lane, London. Pigs. 1 and 2 are 



FIG. 



Models of Hammers. 



of the forms recommended by the late Dr. M'Culloch ; fig. 3, 

 is known by the name of Sedgwick's, and fig. 4 by that of 

 De la Eeche's geological hammer. The remaining figures 



