I reply to yours of yesterday.

I don’t understand what is now wanted in the way of estimates other than parts of what you prepared last year or why you should revise those then made except as required by the rise in price of iron &c.

I am much disinclined to abandon any of the propositions which you place in question;

As to the bridge over the railroad, of course grace and symmetry and especially continuous unity of motive must be regarded as primary objective points {equally with safety and convenience of transit.} A broken curve in the curb of the drive, that is to say, would be displeasing. And if the parapet of the bridge is not set parallel with the curb, or at worst if it is not a chord of its curve & this symmetrical, (showing unity of design with it) the awkwardness would be a constant offence to a nice eye.

On the whole I would prefer a girder construction below the floor at the expense of a slight increase of grade in the approaches from Commonwealth Avenue. The law would oblige the underside of the girder to be 18 feet above the rails, I believe. The distance to be spanned is, say, 85 feet, but of this less than half is occupied by the rails and their bed. I asked some railroad man, probably Mr. Rockwell, whether something might not be gained in piers or brackets upon the 20 feet or more of spare space on each side {of} the tracks? He thought it could by consent of the Company. I would go to any trouble, even that of getting a special permissive act, to gain all that is thus possible and then adopt the lowest girder construction consistent with safety. This construction I would take as a platform to build the superstructure of the bridge upon, maintaining all curves both vertical and horizontal in the top work exactly as if working on an earth bed.

The less people passing {over} this bridge are aware that they are off [448]

Section of plan showing northern section of Back Bay Fens (Boylston Street Bridge to Commonwealth Avenue), March 5, 1879

The Boylston bridge will be the most conspicuous object in all the scheme. It will be forced on the attention above and below and on each side. It will dominate everything & be seen from Charles River to Parker Hill. People will rest & lounge upon it & look at it more closely than anything else on the Bay. A natty, formal elegant structure would put all rural elements of the Bay out of countenance. It would be a discord. The bridge must, if possible, have a rustic quality and be picturesque in material as well as in outlines & shadows. It does not seem to me that I should want to conceal the spiral lines of the arch. What I would greatly prefer is a long elliptical arch of rough stone and I do not think I should want to conceal the spiral lines as you suggest. The more the real structure is evident the better. I would like an arch of Roxbury pudding-stone; or an arch of boulders, or of rough field stone, with voussoirs &c of cut stone or brick; or an arch wholly of cheap rough brick. I would much prefer wood to iron. I would not at all object to a timber bridge of almost the simplest and cheapest possible construction. I would with such a bridge prefer greater distance between the abutments than the printed plan calls for and two or four timber piers on iron piles, making three or six spans. If such a bridge could be made to last with moderate repairs fifteen or twenty years would it not be fairly economical? After that the question of a stone arch could come up again. I should certainly like a wooden bridge in this situation [449] much better than the most beautiful iron bridge. Let us have iron everywhere else if economy requires but on Boylston Street, though I would always prefer a brick arch or arches at the same cost.

As to the Commonwealth Avenue bridge, I would say the same as of the railroad bridge. Let us have, that is to say, girder construction, if you please, but a superstructure maintaining curves as on the printed plan (and more accurately on diagram enclosed). Have three spans if required but a single central pier is to be avoided if practicable. Two are much to be preferred. Head room below is of no importance but I should think that two piers, and a simple beam construction would appear best.

You will find enclosed a diagram showing plans & positions of bridges and radii of curves.

Before making up my mind more definitely about designs of bridges, especially Boylston Street Bridge, I should want to take counsel with an architect. If you think it desirable to further settle conclusions before making your report let me know & I will come on but I want, if I can, to be here now till Friday.