50 
THE MODERN CEMETERY. 
A Talk on Road=Making, 
Many of our American parks and garden cemeteries contain 
excellent examples of what a good stone-road suited to our cli- 
mate should be like. Having observed the fine condition of the 
drives in Forest Lawn Cemetery, of Buffalo — a magnificent 
garden burial-ground embracing near 600 acres of land — the 
editor of American Gardening, which was given as follows in a 
recent issue of that magazine, and to whose publishers the 
Modern Cemetery is indebted for the use of the accompany- 
ing illustrations asked Mr. George Troop, superintendent of the 
Copyrigiiiec. ; 1 y Kl'KAL PU?L! INC. COMPANY. 
Fig. I.— construction of gutter, coping and pavement 
grounds, for information about the construction of the roads. 
The first question to be determined in road-construction is 
the proper kind of roadway and the depth of the material. 
Roads made only of small stone, however carefully laid and com- 
pacted together, are found not to be so durable in this country 
as they are in Europe, where so many good roads of this class 
were made by Mr. Macadam, who first built them, and built 
them so systematically and extensively, that this kind of pave- 
ment is still called by his name even when, as is now generally 
the case, only the surface coat is built with Macadam stone. In 
this country the power of the frost is so destructive every winter, 
and the road-bed becomes so spongy each spring as the frost 
thaws out, that a pavement of small stones only has little bond. 
The small stones sink too readily into the soft subsoil under 
heavy loads, and a corresponding rut is at once made on the 
surface. The cohesive power of the pavement being once broken 
it yields under further travel on the same principle that an arch 
settles when the keystone is removed. 
For these reasons all good roads of the kind usually known 
as “Macadam roads” have a carefully laid rubble-stone founda- 
tion . This method was at first practiced extensively in England 
by an eminent engineer named Telford. All our so-called 
“Macadam’Voads of any value are of this class,andare sometimes 
named “Telford Macadam.” Figure i shows a cross-sectional 
view, including the gutter and copings, of a portion of Telford 
road-bed 18 inches thick. Its construction consists in first laying 
a foundation of any rough rubble-stones of convenient size for 
handling, and placing them carefully by hand in parallel courses 
across the road-bed as for a rough street pavement. The nearer 
such stones can be brought to the general form of paving-stones 
by judicious breaking, the better the work. Blocks averaging*6 
inches in thickness by 12 inches in depth will make strong work, 
however rough their general shape . They should be placed on 
edge, with the largest edges down, and be set as closely and 
firmly together as their rough shape will permit . Where the 
jagged upper edges project too high for the established thickness 
of the layer, they should be broken off, and all low places should 
be filled with suitable chips well packed into place. The whole 
course should be gone over, and all open spaces be filled by 
running stones of suitable sizes into all interstices with pounders 
or heavy hammers. When the surface is level enough for rolling 
the heaviest roller obtainable should be used, and the rolling be 
continued until the whole foundation course is perfectly solid 
and of the right shape and height to receive the Macadam 
course; that is, the course of small stone. 
The depth of this course of small stone will vary with the 
same circumstances which determine the whole depth of the 
pavement. Usually it is about one-third of the whole. Thus it 
will be 4 inches thick if the Telford course be 8 inches, and 6 
inches if the foundation be 12 inches deep. The stones may be 
laid in two couises if the depth be 6 inches, and each course be 
rolled separately. For the lower course the stones should all be 
small enough to pass through a 3-inch ring, and through a i 
inch ring for the upper coat. To make at once a smooth and 
firm surface it should be dressed with an inch of fine stone screen- 
ings or selected gravel of similar quality. This should contain 
some fine sand or earth loam, just sufficient to sift into the finer 
chinks and to bind the Macadam stones into one firm crust when 
well watered and rolled. 
For the best work a steam-roller is necessary at every stage, 
and each course should be rolled until no further impression can 
be made, or, in other words, until the roller leaves no track be- 
hind it. Horse-rollers, however heavy, are very inferior, because 
the stones shift so easily under the horses’ feet. The heavier the 
draft the greater the disturbance will be. Another defect is tho 
frequent turning necessary, and the impossibility of packing 
firmly the parts of the road where the horses turn. For ordinary 
cemetery use a steam-roller of from 5 to 10 tons will suffice. In 
compacting the surface coat, frequent sprinkling is also neces- 
sary. Both sprinkling and rolling should be continued together 
or alternately until the surface becomes perfectly solid. If, 
finally, the water from the sprinkler be all shed into the gutter 
by a water-tight surface, so much the better. 
A common error in road-making is to have the pavement 
too shallow. It must be strong enough to withstand the heaviest 
traffic to which it may be subject, without yielding when the 
frost thaws out in the spring. Where the subsoil is exceptionally 
sandy or gravelly a depth of 6 to 9 inches might answer fairly 
well, but under ordinary conditions a 12 to i8-inch depth is nec- 
essary for a cemetery road subject to much travel, while public 
highways should ordinarily be still thicker. Few are aware of 
the great difference in power to support a load between a firm 
layer 6 inches in depth and a compact mass 18 inches deep. The 
surface pressure of the passing vehicle will spread through either 
layer, as shown in fig. 2, in the form of a cone with its apex at 
the wheel and its base on the road-bed. The area of this base 
will increase (to use an engineering term) “as the square of the 
depth.” Thus, if the depth of the stone be '6 inches, the weight 
of the road-bed under the stone will be over 36 inches. If the 
depth be 12 inches the base will measure 144 inches; if 18 inches 
deep the weight will spread over an area of 324 square inches. 
Thus a pavement of 18 inches 
is nearly ten times as strong 
as one of 6 inches, instead of 
being only three times as 
strong, as most people would 
naturally suppose. In a like 
ratio is the powerto resist the 
upheaving of frosts, especially 
if the road and road-bed be 
well drained. 
The question of depth be- 
ing decided for any given 
case, the excavation at the 
sub-grade level should con- 
form as nearly as possible to 
the established grade of the finished road, both in profile and 
in cross-section, as shown by fig. 3. 
TIRE 
/ 
\ 6 INCH BED 
/ 
\ 12INCHBE0 
/ 
18'.INCH BED 
Copyrighted : By R, P. CO. 
Fig. 2. — showing how the 
STRENGTH OF A ROAD IS 
PROPORTIONAL TO ITS 
THICKNESS. 
