PHOTOGRAPHING FORESTS FROM THE AIR 



BY LIEUT. LEWIS, R. A. F. 



SO FAR as I know, air photographs have not been 

 used up to the present, for other than war work, and 

 my experience with them has been entirely in that 

 sphere. Such marvelous results were obtained from 

 them during the course of the war, particularly during 

 the latter part, when planes, cameras and operators were 

 more efficient and ground interpreters became more 

 familiar with their work, that I think it is the duty of 

 those of us, who became experienced in their use, to 

 pass that experience on to those in commercial life, who 

 are most likely to find it of value. The timber industry 

 seems to me to be one in which their use has great 

 p o s s i bilities. 

 For about a 

 year of my 

 stay in France, 

 I was employ- 

 ed in the Intel- 

 ligence Depart- 

 m e n t , and 

 among my 

 duties was the 

 i n t.erpretation 

 of aerial pho- 

 tographs and 

 the transfer- 

 ring of infor- 

 mation thus 

 gained, to our 

 maps. Of 

 course we al- 

 ready had 

 maps on the 

 country as it 

 was before the 

 war, but the 

 defensive 

 works con- 

 structed on 

 both sides 

 would have necessitated elaborate surveys which, of 

 course, it would have been rather dangerous to attempt 

 in the vicinity of the front line trenches. By experience 

 we learned to know the appearance on a photograph of 

 the numerous defensive works in the enemy lines, trench 

 systems, machine gun emplacements, trench mortar em- 

 placements, gun pits, dug outs, wire entanglements, tele- 

 phone lines, buried cable lines, and many other construc- 

 tions became known to us, and the result was that our 

 artillery could deal with these things, and the Canadian 

 artillery have a decidedly efficient way of dealing with 

 things that are bothering their brothers-in-arms, the 

 infantry. 



The average height from which these photographs were 

 taken was from 6,000 to 8,000 feet. Now, if such accurate 

 1206 



AN INDICATION OF WHAT THE AEROPLANE CAMERA MIGHT DO IN MAPPING THE FORESTS 



OF CANADA 



There is a lamentable lack of forest maps in the Dominion. Some aviators claim they can distinguish 

 tree species by examining stereoscopic photographs and by other methods. This, of course, would be 

 only of general value and the ground cruise would always be necessary. Note the remarkable boldness 

 of outline at 15,000 feet. (A photograph taken on the French front.) 



results could be obtained at these heights how much more 

 could be done with photographs taken, say from 1,500 

 feet, with nothing to ruffle the nerves of the opera- 

 tors ? 



I understand that the Government is to establish an 

 aeroplane or hydroplane forest patrol for fire ranging 

 purposes. Why not have these planes fitted with photo- 

 graphic outfits for the purpose of mapping that part of 

 the country of which so little is known? The importance 

 of it to the lumber industry seems to me, although not 

 a lumberman, to be too great to be overlooked. I have 

 found an idea of how this work might be done for the 



lumber c o m - 

 panies. 



They might 

 make arrange- 

 ments with the 

 Government to 

 have their own 

 limits photo- 

 graphed, mere- 

 ly paying rent 

 for the machine 

 while on their 

 work, and the 

 cost of the 

 phot ographs, 

 approximately 

 $4.00 per doz- 

 en. This would 

 cut out the nec- 

 essity for hav- 

 i n g machines, 

 operators, and 

 cameras of 

 their own. 



First of all, 

 take the tim- 

 bered area 

 which carries a 

 variety of trees, it need only be a small area. Have it 

 accurately cruised, or better still, have a survey made of 

 this one small area and have species of trees given and 

 also condition of ground as to rock, outcropping, etc. 

 Then have this area photographed at two seasons of the 

 year, preferably in the spring, before the leaves come out 

 on the deciduous trees, and then again when they are 

 in full leaf. These photographs will be taken from a 

 known altitude in order to arrive at a scale. Have them 

 carefully analyzed in every detail and records made. 

 They could then be used as standards in analyzing pho- 

 tographs of any tract of timber land, and I am quite sure 

 that an accurate estimate could be made of standing tim- 

 ber, burnt over areas, areas fit for forestation and re- 

 forestation and also the water in the vicinity. If photo- 



