396 ARCHJEOLOGY. 



a considerable space and thoroughly examined at various depths, the 

 results, if any, being kept separate and marked accordingly. Where 

 a stalagmitic deposit, such as is common in limestone caverns, forms 

 the floor, it must be broken up and its thickness measured. The un- 

 derlying materials should then be cautiously removed and sorted over, 

 each layer being kept by itself, and where any remains are discovered 

 the utmost precaution should be taken to determine their actual cir- 

 cumstances. If, for instance, they are bones of men, it should be 

 ascertained whether the skeleton is entire and in a natural position, 

 indicative of having been buried there, or scattered, as also its posi- 

 tion relative to any other remains, whether under or over them; if of 

 animals, whether they exhibit the marks of tools, and above all, evi- 

 dences of the employment of fire. Every fragment of bone or other 

 evidence of animal life should thus be preserved and marked with 

 the order of its succession in depth. 



The same precautions should be taken in the other cases mentioned, 

 the conditions under which the objects are found, and the depth and 

 character of covering of each being noted, and full sets of specimens 

 sent for examination. 



CIRCULAR, 



Smithsonian Institution, 



Washington, April 25, 1862. 



The Smithsonian Institution is about to publish a communication on 

 the ancient mining operations of the Lake Superior copper region, 

 and is desirous of obtaining all the facts which have been discovered 

 in later times in regard to this subject. 



To attain this object, it is respectfully requested that all persons 

 who have made original observations in regard to this matter will 

 send an account of them to this Institution, and also specimens of 

 implements, &c., of wood, stone, or copper which have been found 

 in the vicinity of the ancient mines. These specimens w411 be care- 

 fully photographed and the originals, if requested, be returned to the 

 owners. 



Specimens and photographs of this kind, when collected together, 

 afford the means by comparison of inferences of much interest in re- 

 gard to the early history of man, particularly in connexion with the 

 investigations of a similar kind now being prosecuted in Europe. 



Mr. Jacob Houghton, mining engineer, Houghton county, Michi- 

 gan, has kindly offered to take charge of any articles which may be 

 presented or lent to the Institution, and they may be forwarded 

 through him, or directly by Adams's Express, at the expense of this 

 establishment. 



JOSEPH HENRY, 

 Secretary Smithsonian Institution. 



