2 is achieved through the 
nd Chi-square tests have 
ould like to see pursued 
h a statistical design had 
t difference in measuring 
he solution was unsatis- 
the men performing the 
ree heights with a paral- 
gnificant results could be 
t that the average inter- 
fore attempting work of 
ment that transparencies 
icy was designed to find 
e factor of measurement. 
ne difficulty was, to the 
he interpreters, not from 
equately trained to inter- 
: of 1/15,000 to 1/25,000. 
ther agency likewise was 
e volume as the basis of 
the same as in the pre- 
rstanding regarding the 
ne time of year. Further 
is strip photography has 
y for our purposes. 
st part by means of the 
means of a factorial type 
| try out several series of 
uited to a pilot type of 
hat have been mentioned 
to cruise timber directly 
pensive ground work. 
id work is a necessity in 
pe and other subdivision 
iccurate will be the final 
ume table construction, 
ne time. 
tect, the percent of each 
ber, timber quality, and 
(531) 
Inasmuch as all of the last mentioned data can be secured at the same time 
that volume table data are being taken, it is evident that the opportunity to 
reduce costs lies in the elimination of the ground work that is associated with 
type and stand class delineation on the photos. 
The factors that can be suspected of contributing to the ability to make 
as fine a differentiation here as possible, down to say five acres, are film and 
filter combination, scale, acuity and resolution and contrasts in the stand of 
timber itself as between individual tree images and between tree images and 
the ground. Each main timbered region of the country has its own contrasts 
and likewise its own peculiar problems. As for acuity and resolution, an image 
motion compensation camera of high resolution should be used. As for tim- 
bered regions, each region should run the experiment for itself. This leaves 
scale, time of year and film and filter combinations. 
Scales should be tested from about 1/3,000 to 1/20,000 and not less than 
four should be used. The scale finally decided on may be intermediate to any 
of those tested and by using four scales the opportunity to curve the results 
is obtained. 
The film and filter used should be based on all previous information 
available. They would probably include infra-red, panchromatic and ortho- 
chromatic each with several different types of filters. 
The time of year should be summer and winter as we can not take 
advantage of the contrast coloration in spring and fall on extensive surveys. 
Many other problems ranging from the type of plane used through the 
processing methods of the films can be handled by similarly designed studies. 
It has been pointed out by Tarkington that another variable termed acuity 
can now be measured. While I am not too familiar with this new factor, it 
shows promise of becoming the base to which most of our work can be 
referred. If this hope is borne out it should be possible to obtain optimum 
results from the equipment available for a particular job by referring each 
variable to the acuity base and properly weighting it. 
FOR AN INTERNATIONAL PHOTOGRAMMETRIC ARCHIVE OF 
ARCHITECTURAL MASTERPIECES 
Dott. Ing. Placido Belfiore. 
The artistic patrimony of human knowledge is a treasure of culture, for 
meditation and for the progress: it is not a property of nations, each one in 
particular, but of whole human kind too. 
We must therefore preserve it, in spite of whatever present or future 
adverse event, by means of a collective trial and with a willing and speedy 
interest. | 
Unluckily we cannot preserve natural beauties from calamities; not even 
some of the manual works, as pictures, hardworks and wooden riggings, as 
they are exposed, practically without protection, to prejudices of time and 
weather. 
The photogrammetric method now allows a better protection and a 
perfect study of two branches of artistic produce: sculptures and architectural 
monuments.