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THE POPULAR SCIENCE MONTHLY. 



ent manufacture. The graphite was sawed 

 into small sticks and these were inclosed in 

 wood. The Cumberland pencil was regarded 

 till about the beginning of our century as 

 unsurpassed, distinguished by an extraordi- 

 nary softness and delicacy in the drawing, 

 and was extremely costly. Only the best and 

 purest material being used, this was exhaust- 

 ed in a relatively short time, without any new 

 source being discovered. At last, manufact- 

 urers began to pulverize the waste and to 

 mix it with other materials, to press the mass 

 into hard cakes and saw it up in the old way, 

 without getting a pencil in any way compar- 

 able with the old Cumberland brand. New 

 beds of graphite were, however, discovered 

 in Bohemia, the product of which was still 

 far inferior to that of Borrowdale. After 

 some time the art was learned of purifying 

 the Bohemian graphite by a careful chemical 

 process ; and toward the end of the last cent- 

 ury the happy thought occurred at once to a 

 French and a German manufacturer of mix- 

 ing purified graphite, finely ground, with 

 moistened clay. The invention was useful in 

 three ways : by reducing the cost of the pen- 

 cils without impairing their quality ; by mak- 

 ing it possible, through variations in the pro- 

 portions of the ingredients, to give the pen- 

 cils different degrees of hardness; and by 

 simplifying the manufacture, so that pencils 

 became cheap and within the reach of all. 



Native Types in Abyssinia. — Traveling in 

 Abyssinia, M. Jules Borelli was most struck 

 with the multiplicity of the native types, and, 

 in fact, with the entire absence of a pure 

 type. Thus, it seemed impossible to find a 

 regular Abyssinian type at Shoa. This is 

 possibly accounted for by the fact that four 

 fifths of the people at least are the sons of 

 slaves of various origins. The sons of the 

 daughters of nobles, who pretend to be of 

 the pure race, are most frequently grandsons 

 of slaves. In many places cloths and arti- 

 cles of silver were found, bearing designs 

 that pointed to an Oriental origin, which 

 seemed to indicate that, long before the rise 

 of Islam, southern Arabia was occupied by 

 Persians. These were the first Asiatic races 

 which, passing the Red Sea, drove back be- 

 fore them the black races, while they min- 

 gled with them, forming those innumerable 

 varieties which now make a classification of 



native types impossible. The multiplicity of 

 languages spoken in these regions is another 

 consequence of these invasions and crossings. 



Glacial Moraines in Illinois and Indi- 

 ana. — In a paper on the Glacial Phenomena 

 of Northeastern Illinois and Northern In- 

 diana, Mr. Frank Leverett describes the mo- 

 raines as terminal to the ice, but not to the 

 drift-covered areas of those States. Four 

 proofs of advance in the production of later 

 moraines are cited : Buried soils in situ be- 

 tween till sheets; changes in the direction 

 of flow as shown by striae ; change in the 

 form of the ice lobe, as indicated by the dis- 

 tribution of the morainic belts and the shift- 

 ings of the re-entrant and lobate portions ; 

 and evidence of push or advance found in 

 the moraine itself. The number of distinct 

 moraines varies because of partial coalescence 

 or local obliteration of portions of certain 

 moraines by later advances. For this reason 

 correlation is difficult. Aside from this, there 

 is an increase in complexity in passing from 

 older to newer moraines. 



The Stone Hand-hammer. — A special 

 study has been published by Mr. J. D. Mc- 



Guire, of Ellicott City, Md., of the stone 

 hand-hammer, which he believes was proba- 

 bly the tool upon which races living in the 

 stone age relied more than upon any other 

 object to fashion other stone implements. 

 There is no implement, he says, more com- 

 mon among the relics of the stone age, none 

 the uses of which have been less discussed 

 by archaeologists, and none more deserving 

 of thorough discussion. The objects seem 

 to be comprised in three types : First, a flat- 

 tened or oblong ellipsoid, having a pit on one 

 or both sides, the pits being probably in- 

 tended as finger-holds to relieve the index- 

 finger from the constant jar occasioned by 

 quickly repeated blows on a hard surface. 

 The periphery of these will often be found 

 quite smooth, at other times rough, accord- 

 ing as it has been last used as a hammer or 

 as a rubber ; for, besides using the hammer 

 to peck his axe or celt into shape, he after- 

 ward polished his implement with it. Often 

 one or both of the flattened sides show the 

 effect of rubbing. A second type is the 

 spherical implement, slightly flattened at the 

 poles, showing a battered and commonly a 



