574 



THE POPULAR SCIENCE MONTHLY. 



a covering for his frizzly hair. On another 

 visit from the natives, one was horrified at 

 seeing salt beef in a cask, and another was 

 terrified at seeing his own ugly reflection in a 

 mirror. They had become tired of the white 

 men by this time, and signified it by waving 

 their arms down-stream. " One very old and 

 wrinkled man rubbed his nose and pinched 

 the tip of it, and rubbed the pit of his stom- 

 ach. Another signified by signs the act of 

 cutting off the head and arms, using the 

 words ' oorar ' and ' badinar.' " With a tribe 

 called Kiwa Pori, in the delta of the Queen's 

 Jubilee River, one of the signs was to hide 

 their lowered heads in their hands and then 

 to draw their hands down ever cheeks, mouth, 

 chin, neck, breast, and abdomen. These 

 men were of unusually fine stature, and dark 

 bronze in color ; but, though with well- 

 nourished and muscular frames, " their re- 

 treating foreheads and heavy eyebrows gave 

 them a sinister expression." One tribe al- 

 ways spoke the name of the sun in a whis- 

 per, with finger pointing upward and averted 

 gaze. In a deserted hut, which exceeded the 

 others of the village in size, was found fixed 

 up in front a " taboo," consisting of a painted 

 mask resting on a large circular wisp of 

 sago -palm fiber and rattan, with pendent 

 streamers of the same fibrous material ; 

 while half-way down the floor of the hut 

 were bones of fishes and small deer sus- 

 pended from streamers. All of the new 

 tribes wore nose-pencils, distended the lobes 

 of their ears, and smoked sun-dried tobacco 

 by means of bamboo tubes. The canoes of 

 all the tribes were dug-outs, with either a 

 bank of mud or a small boy squatting in 

 the prow and opposing his back to the in- 

 coming water. Some of them were very 

 large. In one, twenty-nine men stood up to 

 paddle. 



Polishing Telescopic Objectives! — The 



shaping and grinding of telescopic objective 

 lenses are operations requiring great care and 

 delicacy in execution. In polishing, softer 

 powders and softer tool-surfaces must be 

 used than in grinding. Of all the sub- 

 stances that have been used for the face of 

 the polisher, pitch, or the natural bituminous 

 deposit from Archangel, which was first 

 employed by Sir Isaac Newton, is, accord- 

 ing to Mr. Howard Grubb, still the best. It 



has the important qualities of perfect inelas- 

 ticity and a property of subsidence. Cloth 

 can not give a perfect surface, because it is 

 apt to round off the edges of the pits left by 

 the grinding-powder, and to polish their bot- 

 toms as well as the real surface of the lens. 

 Pitch wears away the surface evenly, and 

 does not take hold of the pit-bottoms till 

 the whole is ground down to a level with 

 them. Although pitch, by boiling, can be 

 made so hard that an impression can not be 

 made on it with the finger-nail without split- 

 ting it in pieces, it will, even in this con- 

 dition, if laid on an uneven surface, in time 

 subside and take the form of whatever it is 

 resting upon. This property, by virtue of 

 which it may be considered technically a 

 liquid, is taken advantage of in the manipu- 

 lation of the polishing process to produce a 

 surface exactly even and true. It appears 

 to be peculiar to pitch, some of the resins, 

 and ice ; although it has been observed, in a 

 vastly inferior degree, in some metals. It is 

 a curious circumstance that the same quality 

 which in ice allows gradual creeping and 

 subsidence, and the consequent formation of 

 glaciers, should in pitch help us to produce 

 accurate optical surfaces. 



Italian Butter. — The Italians do not ex- 

 cel in the manufacture of butter. It is pro- 

 duced considerably only in four districts, of 

 which Lombardy furnishes the best, usually 

 through the market of Milan. The butters 

 of Reggio and the Tyrol are used for mixt- 

 ures, and those of ^Emilia and Sorrento are 

 unimportant in quantity. In the rest of the 

 country, oil, fat of American origin, or sub- 

 stitutes are used for daily wants. According 

 to the French consul at Milan, the principal 

 obstacle to the development of the trade in 

 pure butter is the increasing use of these sub- 

 stitutes, and artificial butters, which are im- 

 ported from America, France, Germany, Eng- 

 land, and the Netherlands. " The demand 

 for butters in Europe, South America, Aus- 

 tralia, India, Japan, and even China, has 

 become so important that, in presence of the 

 insufficiency of the natural product, it be- 

 came necessary to manufacture an analogous 

 substance, so that in Holland and Denmark, 

 the principal countries producing pure but- 

 ter, the artificial butter industry was under- 

 taken without fear of prejudicing the pure 



