AND GROUNDS. 
227 
tunnel. But by mounting a bridge, although we thus secure clean 
footing at all times, which might not be the case in crossing on the 
ground, the alley would be more entirely in sight than if one were 
to cross it in the usual way ; and (if the bridge were uninclosed) 
persons making use of it would be targets for the eyes of the 
neighborhood. If inclosed and roofed, its height would make it 
absurdly conspicuous, expensive, and liable to be carried off by 
winds. Whether used or not, it would stand obtrusively in sight 
from all directions, without the excuse for its conspicuousness which 
attaches to a wind-mill, which, to be useful, must stand on tip-toe to 
catch each wandering breeze. 
The tunnel, on the other hand, is unobtrusive, out of sight of all 
but those who use it, private, and a cool summer retreat. It forms, 
when properly constructed, a novel contrast and foil to the sunny 
garden to which it is designed to introduce the passer. Descend- 
ing into its vaulted shade, the view on emerging into a sunny 
pleasure-ground is made doubly charming by the contrast. Its 
sides should be recessed for seats, which in the hottest days of 
summer will have a delightful coolness, and in winter form good 
places for storing half-hardy box plants, bulbs, and small trees. 
One needs but call to mind the charming tunnels for foot-paths in 
the New York Central Park to imagine the beauty that may be 
given to even such small tunnels as the ones here recommended. 
If well constructed, such tunnels cannot be done cheaply. But 
in a case like the one under consideration, where the owner of a 
fine place must either sell out and improve elsewhere, or else 
devise some mode of utilizing the lots across the alley, the expense 
of a tunnel and its appropriate adjuncts, will be very small com- 
pared with the sacrifices that would be necessary to secure the 
same benefits by removal. 
The construction of such a tunnel and its approaches requires 
the employment of a very good architect. To enable the reader to 
have a better idea of the plan, as indicated on our plate, we will 
give some explanations in detail. Nine feet below the surface of 
this alley is supposed to be deep enough for the floor of the tunnel. 
Seven feet clear will be high enough for the inside passage, which 
will leave enough earth over the top of a brick arch to protect it ; 
