OF BRIDGES AND VIADUCTS. There are two obvious uses for a bridge; the first is, to pass over; the second, to pass under; the first is always necessary, the other only occasionally so, or where the water under the bridge is navigable; yet, self-evident as this fact may appear, we often observe bridges raised so high, as to make the passage over them difficult, when there is no passage under them required; and this is the case with the present lofty bridge at Woburn. The construction of bridges has been so often and so ably discussed, that it is dangerous to attempt anything new on the subject; yet I think such a form, adapted to the purposes of passing over, as may unite strength with grace, and use with beauty, is still a desideratum in architecture. The consideration of this subject has led me to insert the following short digression, which will not, I hope, be deemed wholly irrelevant.
