REPORT OF THE SECRETARY. 35 



illustrative of the remains of ancient industry; first, for the formation 

 of a collection as perfect as possible to be preserved in the national 

 museum; and second, for duplicates to present to other institutions, 

 with which we maintain relations of reciprocity. It may be observed 

 that, in making exchanges of specimens, the object is not alone to 

 enrich our museum, but to furnish the means throughout the world 

 of a more comprehensive comparison, and consequently to facilitate 

 the study of the various stages of the development of human inven- 

 tion. 



During the past year large and valuable collections have been 

 received from the northwest coast and from w^ithin the Arctic Circle, 

 illustrative of the Indians and Esquimaux of these regions. We 

 have been particularly desirous to awaken an interest in the explo- 

 ration of the shell-heaps which have been found at various points 

 along our coast. These are now known to be of an artificial character, 

 and are frequently rich in specimens of the industry of the earlier 

 inhabitants of this country. As to the archseological value of these 

 shell-mounds, considerable difference of opinion prevails. They are 

 even regarded by some as the work of known tribes of Indians, con- 

 cerning whom we possess other and better sources of information; 

 but, even if this be so, they would serve to illustrate peculiarities of 

 customs, and should, in all cases, be explored and the materials 

 found in therm carefully preserved. From the specimens derived 

 from the shell-deposits on the coast of Norway, the Scandinavian 

 archasologists were enabled to divide the stages of civilization into 

 three principal periods, namely: the stone age, the bronze or transi- 

 tion age, and the iron age. These divisions have been generally 

 admitted as characteristic of the principal stages of human develop- 

 ment, though they are not regarded as successive periods in the 

 generjil advancement of the world, since the inhabitants of one country 

 may be in the condition of the stone age, while those of others are in 

 the full enjoyment of all the advantages of the iron epoch. - 



This division furnishes a ready means of classifying the various 

 archaeological objects, so as to exhibit the comparative civiliza- 

 tion in different places at the same or at different epochs, and, 

 though it may be superseded by a more philosophic classification, it 

 forms an important step in the gradual advancement of a new sci- 

 ence. Indeed, it has lately been proposed to divide the stone age 

 into two — the palceolithic, or first stone age, and the neolithic, or 

 second stone age; and from the discoveries which have been made 

 of late, and which have been so cumulative, we can scarcely 



