prac- | Though there are also applications of the proceeding per block for cartographic 
  
t the problems at large scale (in this connexion, see the communications from Great Britain, 
| Holland, Switzerland) the largest part of proceedings per block is the one for small 
tters scale cartography, from 1: 25.000 up to a maximum of 1 : 200.000. 
ment In these applications, the most important and really astonishing contribution is 
the one given by the French I.G.N. (Institut Géographique National) stating that, 
ljust- in four years only, they have triangulated (per blocks) 608.000 km? for a total amount 
of 25.000 photographs. 
ly do b) table N° 5 contains all information we received: from the same it is difficult 
rtant to generalize some outstanding tendencies. 
g nu- 
"slon 
Flight. - Unfortunately, we have very scanty information: only a more frequent 
use of plate cameras 1s noted together with the apparatuses for determination when 
von flying of the orientation elements (auxiliary instruments). The instruments commonly 
ntro used are: the statoscope and the A.P.R. 
E An American Organization and a Dutch one inform us that they have carried 
1alize 
out triangulations per blocks with converging cameras. 
Adjustment. — The instrumental bridging proceedings and criterions of the control 
| PER point determination, have no remarkable characteristics. 
Considerable characteristics are noted with the adjustment methods that in a 
way, constitute one of the most complex phases. 
yhich The French 1.G.N. adjustes its blocks by a method already communicated in 
ately preceding Congresses, constising in a particular application of the stereotemplet for 
) the planimetry of the block and graphic methods for the altimetrical adjustment. 
dings [n these last years, it has been largely spread the adjustment method conceived 
auto: by Dr. H. G. Jerie of the International Training Centre of Delft. 
lock. This method requires the use of an analogical computer adjusting the blocks by 
both means of the least square method. According to what communicated in the Dutch 
onlv. Report, the results attained by this method, are promising. 
>ast From news contained in the Swedish Report, we take knowledge that in some ca- 
—: ses, the block adjustment formed by independent models and already levelled on points 
of a known height, was obtained through a similar transformation of instrumental 
esta- coordinates on ground points coordinates. 
Graphical and analogical methods of block adjustment, ruled during the past 
se re- quadriennium: however, from some information and statements received by big 
. the Organizations (I.G.N.) it is already outlining a future strong application of electronic 
aceed computers for the computation of block adjustments. 
i 
h the Location of points. — In the proceeding of triangulation per blocks, the preparation 
ved, of photographs is very important and particularly, the research and location of points 
lower common to adjacent strips. 
[n many cases it is impossible their independent location on plates of adjacent 
ther- strips: it is therefore, applied the marking on plates. 
ocee- In this connexion, the Dutch Report is communicating that at the International 
Training Centre it has been built a very cheap apparatus for the statoscopic transfer 
port, and the simultaneous marking of points on adjacent photographs, obtained by near 
strips. 
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