72 BULLETIN OF THE 



He then introduced Mr. Mason, of Baltimore, who exhibited 

 apparatus which he had devised for determining the explosive 

 character of kerosene oils, and made experiments on several sam- 

 ples, showing the temperature at which the vapor of each would 

 flash on the approach of a lighted match, and that at which the 

 oil would begin to burn. The fiashing test gave temperatures 

 about 20° F. below the fire test, and the latter was several de- 

 grees below the standard of 110° F., with which the samples 

 were marked. 



Mr. O. T. Mason continued his paper upon 



THE INTERNATIONAL SYMBOLS FOR CHARTS OF PREHISTORIC 

 ARCHAEOLOGY. 



He said that they sufficiently answered the characters of sim- 

 plicity, distinctness, speciality, and mnemotechny. As to their 

 universality, it was necessary for them to be not only universally 

 legible, but also universally applicable. In this sense they were, 

 in the first place, restricted to Europe principally, and even there 

 failed to mark either a built-up wall, or a place of sacrifice. For 

 the wall Mr. Mason proposed the sign | -l-1-| , and for a sacrifice 

 \ \. In order to make the signs apply to America several addi- 

 tions would have to be made. To supply the want of a sign for 

 an ossuary, the symbol grave is taken with a plus in the centre. 

 A tribal lodge is indicated by the six-pointed star with a plus 

 inclosed; an animal mound by the mound sign with the plus 

 inclosed. Mr. Mason concluded by urging geologists of the 

 National Surveys and others to give a portion of their leisure to 

 the location and description of the antiquities of our country. 



Mr, Powell followed with remarks on the very little know- 

 ledge that could be gathered from relics ; and Mr. Gill on the 

 information to be derived from animal remains. 



105th Meeting. April 22, 187(5. 



The President in the Chair. 

 Forty-eight members and visitors present. 



