72 SCIENCE PROGRESS 



reasonable to suppose that it would be worked before smelting 

 was discovered. What points to this is the pillowy form of 

 tools in the earliest metal age of most countries. This form 

 could not be cast except in closed moulds, but it would be 

 the most natural for hammered native metal. The earliest 

 stage of casting was the mere limiting of out-poured metal in an 

 open mould, and hence flat castings, such as are found in Egypt, 

 and such as appear in other countries after the hammered forms. 

 The order of use of metallic materials, then, seems to be native 

 copper, smelted copper, bronze, iron, steel, and brass. Copper 

 may be hardened by small impurities and much hammering, 

 until it is equal to any bronze ; the main purpose in using 

 bronze was probably to facilitate casting, especially for closed 

 moulds. The cire perdue process also needed bronze, and that 

 was a favourite mode of work, from early Egypt to early 

 Britain. In both those lands the metal was run to an astonish- 

 ing thinness, often only a fiftieth of an inch, a mere film over the 

 sand-core. 



When the variations of the forms of tools in different coun- 

 tries are compared, much is seen to depend upon climate. In 

 the north (figs. 3, 4) sockets are much larger and deeper than in 

 the south (figs. 1,2); this is due to the softer and more stringy 

 nature of northern woods, which would be bruised and crushed 

 in the leverage of a small socket. Neither oak nor ash nor 

 beech could compare with the Syrian sh'um for resisting a 

 wrench. The varying purposes also led to very different forms ; 

 the slight socket and large blade for a fighting axe, when the 

 blade was not gripped in the cleavage ; the splitting axe with 

 a long socket to enable a side-wrench to be given ; the cleaving 

 axe with a long back to the socket (figs. 5, 6) to aid in a lifting 

 pull to get it out of the wood. In the agricultural tools there 

 are clear distinctions between the scythe or sickle worked 

 with a sawing motion from the hand at the end of the blade 

 (fig. 7), or the reaping sickle with a circular arc around the 

 wrist which rotates it (fig. 8), or the pruning-hook to top off 

 high vine-sprays in the south (fig. 46), or the bill-hook to cut 

 copse-wood in the north. The different kind of motion must be 

 considered before we can understand the varying use of each 

 tool. In weapons, similarly, the width of spear or arrow-head 

 is conditioned by the defence. On bare bodies wide cutting 

 blades are the most effective, to attack clothed bodies a narrower 



