Proceedings of the Polytechnic Association. 745 



The transit of passengers, &c., between the surface and the cars 

 will be performed by the elevators, which will regularly ply up and 

 down, one ascending while the other is descending, offering a much 

 more agreeable mode than that of climbing up and down stairs, and 

 in every way as satisfactory and as pleasurable as that by the elevator 

 exhibited at the late fiir of the American Institute, on which so many 

 thousands of men, women and children wei'C seen daily to ascend and 

 descend for mere pleasure. This was one of the great attractions of 

 the fair, and those tunnel elevators will be equally attractive. The 

 movement of the cars and the continual discharge of so much pure 

 air in the tunnel will insure ample circulation and the most perfect 

 ventilation. 



The roof of the tunnel in all parts where masonry is required will 

 be that of a double archway, the middle to be supported by a line of 

 iron columns. In solid rock there will be but one arch. 



Ornamental chandeliers will brilliantly illuminate the whole tunnel, 

 and its temperature will be at all times as we desire, " warm in win- 

 ter and cool in summer." Men, women and children will at every 

 convenience come here to enjoy a ride, which shall be in no way 

 inferior to that of a delightful carriage ride, in clear, airy, and pleasant 

 moonlight, on which the poets so much delight to dwell. 



This plan has been objected to by sundry individuals. Mr. Gstrdner 

 says it is impracticable on account of the quicksands to be encountered 

 at that depth, and also the impossibility of proper ventilation. 



He who speak of quicksands as a serious difficulty in engineering 

 now, is wofully behind the times, and is ignorant of the fact that 

 modern chemistry has furnished us with the ready means of depriving 

 quicksand of its peculiar mobility, and of converting it into a sub- 

 stantial earth, easily spaded, or, if you please, into solid rock. What 

 did he expect to do about the quicksands that might be encountered 

 in the Broadway arcade ; did he suppose it impossible that there 

 could be any there ? 



General Barnard has many objections to all kinds of tunnel ways. 

 But the asperity of his objections is inuch relieved by the kindly 

 manner in which he speaks of the proneness of men to differ in their 

 views and opinions. He says that in practical matters, as well as in 

 religion and politics, one person will think in one direction and 

 another in a direction directly opposite, and with the milk of human 

 kindness and christian charity, he admits that they are both equally 

 honest. 



