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to improvement. Our forest development road program has increased in magni 
tude, thereby making it essential to seek better methods which will partially 
alleviate the shortage of engineers. It is hoped that by utilizing first order type 
stereoscopic plotting equipment it will be possible not only to prepare strip 
topography along the centerline of the road but to read directly x-, y-, and z- 
coordinates of cross-sections. These tabulated coordinates can then be intro 
duced into electronic computers, thereby procuring quantities in this manner 
rather than through the standard method of technicians interpreting contours 
and computing with the aid of a calculator. 
This discussion has been related to forest development roads, the program 
for which has increased to the extent that further shortcuts are essential. How 
ever, there has recently been approved through legislation a highway program 
in the United States which will entail an increased expenditure of approximately 
58 billion dollars by the Federal Government in a ten-year period. This sum 
will be further increased by an approximate 10 percent contribution from the 
states. In view of this increased highway program it is my belief that photo- 
grammetry will be used to a greater extent not only by the Forest Service on 
forest development roads but also in connection with the Federal highway 
program. 
Mr. Welander, Sweden: In Sweden we have a Committee of Forest Photo- 
grammetry which considers all applications of photography to forestry. I believe 
our conditions are about the same as those in Northern IJ. S. A. and Canada. 
We use small photographs plus helicopter reconnaissance for road planning. 
Mr. Losee, Canada: In Canada there has been a tendency recently to locate 
a road approximately by use of whatever aerial photos are available, then to 
select the final exact route by means of a helicopter flying low over the area. 
In many cases the exact location is determined by the position of the road on 
the slope of hills. In many areas, near the base of hills, there are boulder pave 
ments, left as a result of glaciation, and these are very costly to build roads 
through. The other chief factor, is the amount of rock which must be removed 
before you can build a road through, and the effort of course is to minimize 
this without lengthening the road appreciable. 
Mr. Coleman, U. S.A.: Various photographic scales have been mentioned in 
the papers thus far. In Swedish papers the emphasis was on the use of small 
scale photographs. In Holland and U. S. larger scales for forestry interpretation 
seemed to be the rule. I would like to ask Mr. Welander whether in his opinion 
the utilization of the ortho films and filters in the identification of tree types, 
might permit the use of smaller scale photographs. 
Mr. Welander, Sweden: We have taken photographs from 3 000 and 5 000 
meter altitudes, but we have not yet thoroughly checked the results. I believe 
a scale of 1/25 000 to 1/30 000 is best for forestry use. However, I do not think 
the use of orthochromatic film will permit us to use higher altitudes because of 
haze problems. 
L’emploi de la photographie dans les travaux relatifs à la construction de routes dans les 
forêts est discuté. Les photos à petite échelle sont utilisées en Suède et au Canada, en combinaison 
avec la reconnaissance au moyen d’hélicoptères volant à basse altitude. Au Canada les photos sont 
également utilisées considérablement comme cartes de travail par les chefs d’équipe dans la 
construction routière. 
Aux Etats-Unis les plans de nouvelles routes sont très souvent basés sur les études photogra 
phiques. Dans un cas, l’établissement de plans de routes, qui aurait exigé deux ans selon les 
méthodes de lever classiques, a été accompli en six semaines. Les premiers plans sont dressés à 
partir de photos à petite échelle déjà existantes: les plans détaillés sont basés sur des vues 
aériennes spécialement prises à l’échelle de 1/10 000 et restituées à l’aide d’instruments Kelsh.