Scientific Lectures. 187 



pecuniary means. To some extent, therefore, their works belong to 

 the hixiu-ies of the age ; nevertheless it may be said of those of modern 

 times, that they are in an eminent degree those which are of the 

 highest practical value to society. The wealth and prosperity of any 

 country depends upon the skill and amount of its labor, usefully 

 applied. The dense population of semi-barbarous nations, like China, 

 lack this skill and application. The frozen regions prevent, and the 

 torrid ones destroy, the inclination to labor. It is in the northern 

 temperate zones that we find the greatest amount of labor and skill 

 in its application, and through this belt shall we find our chief 

 examples of engineering. It is the peculiar duty of the engineer to 

 instruct and direct labor ; and his value in his calling depends greatly 

 upon his knowledge of, and ability to instruct in, the best methods of 

 applying either skilled or unskilled labor. The works of the ancients 

 are often referred to as excelling in magnitude, accuracy of work- 

 manship, and beauty of design those of modern times. This view is, 

 in part at least, quite erroneous. The engineers of those days were 

 employed by rich and powerful patrons, who furnished them numerous 

 though generally unskilled laborers ; materials without regard to cost, 

 and money without stint. Their works bear evidence of these con- 

 ditions, and were chiefly confined to monuments of useless victories, 

 or constructions in compliance with the whim or caprice of the 

 monarch, or in deference to their idolatrous worship. Yet there are 

 exceptions. The transport canals of Egypt and China, those for 

 irrigation in India and Assyria, the water- works all over the East, 

 the vast military roads which radiated from the Imperial city, and 

 extended to the extremity of the empire, the bridges over rivers, and 

 the ports and harbors of the inland seas, all bear evidence that these 

 engineers were often called upon to plan and execute works designed 

 for utilitarian purposes. While the great canals of China and those 

 of Egypt were but imitations of the natural water courses, without 

 locks, yet many of the other works referred to, and especially those 

 constructed by the Roman engineers, are fine examples of professional 

 practice. In alluding to the great works executed by the ancient 

 architects, mention must be made of the Temple of Baalbec, wherein 

 are found the largest stones (save one) in any building in the world. 

 Three of these measure 68.64J and sixty-two feet in length, fifteen feet 

 in height, and from the fourth corresponding stone yet in the quarry, 

 but broken, the widths are also fifteen feet. Bayard Taylor calls 

 these stones 8,000 tons weight, but l)y the above measurement the 



