694 



Popular Science Monthly 



Army Pistol Shoots Colors 



A DEC ID ED novelty in the way of 

 pistols has been perfected for use by 

 the United States Signal Corps for the 

 purpose of communicating at night. In 

 appearance, the pistol resembles the old- 

 fashioned dueling pistol except that it is 

 lighter and smaller. Cartridges firing 

 spurts of flame of various hues are used 

 for ammunition, the color of the flame 

 carrying a definite message to the 

 distant lookout. 



A One-Pound Diamond 



THE great diamond mines of the 

 Transvaal have been revealing their 

 age-long secrets for many generations, 

 but the greatest surprise of all came on 

 the twenty-fifth of January, 1905, when 



brilliant 

 naments 

 England 

 stone is a 

 brilliant of 

 carats and is the 

 central figure of the 

 English crown. 



Only six months were 

 required for cutting the splen- 

 did stone, advantage being 



of 516I4 carats. It or- 



the royal scepter of 



The smaller 



square 



309V16 



\i 



One and one-third pounds was the weight of the 



famous Cullinan Diamond. It was cut into two large 



gems and over a hundred smaller brilliants 



the Cullinan stone, afterward 

 named Star of Africa by 

 George V, was discovered. 

 When the excited owners 

 placed the colossal gem on the 

 scales they found it weighed 

 621.2 grams, about one and 

 one- third pounds. It was 

 more than three times the 

 size of any diamond ever 

 found before or since, weigh 

 ing 3,025^ carats, and of 

 quality. 



King Edward VII was presented with 

 the stone on his birthday in 1907. Later 

 it was placed in the hands of the famous 

 Amsterdam firm of I. J. Asscher and 

 Company who cut it into two large stones 

 and over a hundred smaller ones. The 

 larger jewel has the exceptional number 

 of seventy-four facets being a drop 



An army pistol which shoots colored light 



taken of the planes of cleavage. 



Disinfecting School Pencils 



IT has long been recognized 

 that the school pencil is a 

 fruitful source of disease. The 

 pencil points are usually given 

 a bath by the child's placing it 

 in his mouth to soften the lead. 

 Then the pencil is passed on to 

 another child, who does the 

 same, thereby spreading all 

 kinds of communicable dis- 

 eases. The pencil is disin- 

 fected by a new system, 

 through the action of formal- 

 dehyde gas upon the bacteria. 



the 



The lead-pencil of every child is a germ- 

 carrier. Disinfect the pencil with for- 

 maldehyde gas, as shown by the picture in 

 the circle, and the spread of disease in 

 schools will be reduced 



