Dear Sir; We have received yours of 6th. We were rather expecting to have some map from you which would enable us to review the course of the Approach Road before giving you the memoranda for which you ask, but it is not necessary. Send us as soon as convenient a topographical sketch of the strip of land to be dealt with between Shiloh road and the corn-field, with the plan of the road laid on it and any suggestions for improvement that you can think of.

Without waiting for further discussion or development of the plan you can go ahead with all preliminary operations until you hear from us, (or until my next visit.)

Assume that the wheelway, exclusive of gutters, is to be 18 feet broad; that there is to be no curve in its course of a less radius than 35 feet, and that its grade is to be nowhere steeper than 1 in 20.

In determining the exact lines of the road, particularly where it is to be [749]built as a shelf thrown out from a hillside, allow space for gutters and for graceful borders etc., as follows:—

(1)   Wherever the surface of the adjoining ground is to be higher than that of the road there is to be on that side a paved gutter ordinarily from 2 to 3 feet wide outside the 16 ft wheelway, This gutter is never to be so deep that a carriage wheel may not be turned into it without inconvenience or danger: as often as necessary to give it due capacity without making it too deep, provision must be made for the diversion of the gutter stream, and this will ordinarily be by an outlet passing under the bed of the road to the brook. The discharge from the gutter may be from an 18 inch vitrified pipe set on end, with a branch leading into the pipe under the road, and with a cast iron grating at the top.

(2)   The surface of the ground outside the gutter is never (under circumstances now anticipated) to rise abruptly or in the form of a {dead} inclined plane from the gutter thus:

but always with a simple or double ogee curve, thus:

(3)   Where the surface rises from the road on both sides, {(as near the Shiloh road)} there are to be two gutters.

(4)   Where the inclination of the bordering ground toward the road is slight, but the slope extended, provision is to be made for intercepting the flow of water down the slope and carrying it off before it reaches the road gutter. Generally this will be by a broad shallow gutter with a {curved} surface.

(5)   Where the slope is too steep for the convenient forming of such a gutter and wherever there is reason to apprehend a {sweeping} flow of water that in the spring would make the ground soft under the road, a trench at least two feet deep is to be dug along the outside of the gutter and filled to within six inches of the surface with rubble stones, from three to six inches in largest dimension, to act as a blind drain; cross drains under the bed of the road being laid at intervals as outlets.

(6)   Where the surface is to rise from both sides of the road and there is no brook into which to carry drainage directly, vitrified pipe is to be laid, ample to take all surface flow, and all gutter water is to be led to it through silt basins.

[750]

(7)   Where the road is crossing from one side to the other, as a causeway, no gutters will be needed but the wheelway is to have a border not less than three feet wide upon which a carriage could be turned out; making, with the wheelway proper, a space {22} feet broad.

(8)   As a general rule where there is to be ground lower than the road at the side of the road, there should be a gentle ogee slope between this lower ground and the level of the road; where the difference of the level is considerable, however, a retaining wall with a parapet will be better. A parapet 2 feet high and 2 feet broad may be had in view. In this case, a border of one foot will be enough between the parapet and the wheelway, and this border space may be paved as a gutter and frequent outlets made through the parapet.

(9)   Wherever the stream is to be crossed by the road, a {capacious} arched bridge is to be had in view, the ends to be of rough, rock-faced blocks with parapets two feet high and two feet thick. As a rule, the channel should be deepened near the bridges and given steep and partially rock-faced banks with a sinuous course. As a rule, also, the road should be graded to rise slightly from both sides toward the bridge.

Topsoil is to be saved wherever ground is broken. Where the road is carried on the hillside, the top-soil can be at once distributed on the upper side of the road.

Within {60} feet each side of the road, all decaying, dilapidated, [751]

spindling-trunked and notably top-heavy or ill-balanced and unhealthy trees are to be removed at once, and conspicuously bad ones within twice that distance. No tree is to be left standing within three feet of the wheelway, but, as pointed out on the ground, the wheelway may, at one or two points be divided and carried on both sides of trees of particular value, there being always a distance of at least three feet between each branch of the wheelway and any tree.

The felling of Beech, Black Gum, Sweet Gum, Sourwood, Chestnut and Hickory trees of more than sapling size is to be avoided as far as practicable; even (where they are of particular value,) by special curves in the course of the roads. All Rhododendrons, Kalmias, Azaleas and other notably fine bushes found in the way of grading work are to be shortened in (Kalmias very closely) and carefully transplanted to points near the edge of the road or of the swampy ground, where they can be left.

Yours Truly