100 BULLETIN 119, U. S. NATIONAL MUSEUM. 



PART IV. 

 EARL5f HISTORY OF LAND TRANSPORTATION. 



The transportation industry had its origin among human burden 

 bearers in every portion of the inhabited globe, and primitive methods 

 are still in vogue in many countries. When man secured control of 

 the animal kingdom beasts of burden were trained to bear loads con- 

 sisting of indivisible or aggregate units too heavy to be borne by 

 human beings, the larger and more powerful beasts being trained to 

 carry one or more persons at a time. 



When it became necessary to move loads too heavy for men or 

 beasts, new methods were adopted, animals being bred and trained 

 for draught. Great weights were transported by animals, which, 

 singly, in pairs, or in greater numbers, were taught by acting in 

 unison to exert great tractive force. 



Under these conditions it became necessary to devise vehicles of 

 different kinds to be used for various purposes. The sled, made in 

 many forms, especially in the regions where ice and snow are found, 

 proved of great value. The movement of the " rolling load," com- 

 posed sometimes of stone columns for buildings, and oftener of lesser 

 weights in the marketing of the products of the forest and the field, 

 required greater ingenuity. The roller under the load, before the 

 invention of derricks, was the method employed in moving the largest 

 stones ever employed by man. As skill and dexterity in the use of 

 tools increased vehicles with wheels were devised and became an 

 important factor in the development of civilization. 



The ability to construct vehicles with wheels has been developed at 

 different epochs and in different quarters of the globe. It is gen- 

 erally believed that the roller is the link which connects the use of the 

 ancient sledge with the invention of the primitive solia wheel. 



The wheelwrights of every nation have devoted earnest attention 

 to the proper combination of wood, leather, bronze, and iron in the 

 construction of vehicles with wheels and axles, suitable at first for the 

 slow movement of heavy loads and later for rapid movement on 

 common roads and turnpikes. 



The perfecting of the wheel has led to the construction of thousands 

 of types differing in the shape of the hubs, spokes, fellies, and tires 

 and in the methods of fitting them together. Vehicles with heavy 

 wheels, composed wholly of wood or of wooden parts held together 

 with rawhide and elastic wood, having hubs lined with iron and tires 

 of the same material, made to run upon axles of steel, now in common 

 use, were not made at the beginning of the nineteenth century. 



As wealth increased advantages to be gained from good roads Avere 

 better appreciated, so that light and strong wheels composed entirely 



