380 REPORTS ON THE STATE OF SCIENCE.—1912, 
obtained from motor licences and from the petrol tax is put mto our 
hands for the encouragement of road improvement, and the ascertain- 
ment by experiment of the best modes of effecting such improvement. 
As regards grants, these are given when any approved improvement 
is executed, and may, according to circumstances, be a half or two-thirds 
or even more of the cost, to be paid on the work being done to our 
satisfaction. Or where extensive works are taken in hand, money may 
be given in loan at low interest, or without interest, repayable over a 
course of years. Roughly speaking, about a million pounds sterling per 
annum is @¥ailable, which forms a most substantial help to road im- 
provement. And as the number of vehicles increases, which it is doing 
by many thousands a year, the product of the licences and the petrol 
tax will increase in proportion. Of course things must move gradually. 
In our first Board year, one single county in the north of Scotland put 
in a claim amounting to £750,000, being equal to the whole income then 
available for the three kingdoms. We cannot meet such claims. 
As regards research, we are carrying on, under our able engineer, 
Colonel Crompton, and our skilled Advisory Board, experiments both 
in the laboratory and on the road. The laboratory experiments are 
directed to ascertain what are the best materials, to determine the 
proportions as regards size and quantity of the substances found to be 
suitable, to fix the proper thicknesses of road crusts according to the 
traffic they have to bear, and last, but not least, to endeavour to 
determine whether any, and if so what, protecting skin shall be placed 
on the surface so as to come between the hoof or wheel and the bearing 
crust to protect it from being attacked directly by the traffic. 
I shall conclude by calling your attention to some of the results of 
recent experiments, by which valuable and practical information has 
been obtained, ensuring that good roads can be made which will keep 
their surface sound for twice as long as the water-bound road, and will 
not become uneven and break into holes as did the roads of the past, 
which were rough, muddy, and dusty according to the weather, deterio- 
rating in a marked manner within a short time after they had been laid 
down, and in times of heavy and continuous rain having their binding 
washed out or carried down to the gutters, or left lying thick at the 
bottom of the slope wherever there was a gradient of any steepness. 
And let it be realised that in proportion to the degree in which improve- 
ment becomes attainable, not only will comfort and convenience be 
augmented, but the wear and tear of horses, of vehicles, and of tires will 
be lessened in a marked degree, and the moving of passengers and goods 
be facilitated more and more, leading to economy in transit. 
Considering what is to be the road of the future, the important 
question is ‘ What shall be the weight-bearing crust?’ and this is 
engaging the attention of the advisers of the Road Board. One thing 
is now universally recognised, that the road of the future shall be a 
truly bound road, in which, whatever kind of stone is used—a matter 
into which there is not time to enter—that stone shall be held to- 
gether by some pitchy or bituminous material, so that it shall be indeed 
a crust and not something which has no real cohesion, and into which 
Macadam’s enemy, the water, can make its way whenever water falls. 
