gency interventions only registered on photograms cannot be 
plotted immediately in order to save the monuments. Therefore 
it is necessary to record the actual state in case of alter- 
nations and to plot it on the spot at least for emergency 
interventions, using and comparing it with older records. 
Reasonably, according to the plotter's position, one will 
produce a series of photograms for the conservation out of the 
danger zone with regard to the later plotting on normal 
plotters and a second one for immediate developing and quick 
plotting on the transportable emergency plotter. Latter plot- 
ting may be less precise than the definitive one. If the photo- 
grams for such a first plot developed in an emergency dark 
room, they may eventually be destroyed later on without any 
important disadvantage for the first plot. 
The small plotter must not be too expensive, so that it can be 
used without hesitation in danger aereas, as one can expect to 
sacrifice it (if need be), if the operators must get out to 
save their lifes and must leave the plotter on the spot. The 
few measurements determinated by such a plotter cannot only 
save, 1f immediately submitted to the competent users, irre- 
placeable, precious objects, but also economize the amount of 
working hours and money which may be much higher than the cost 
price of the plotter. Not only in case of catastrophy, but 
everywhere where central services are concentrated on one of 
few places but where missions are to be executed on distant, 
unapproachable places by highly qualified personnel (high 
mountain regions, swamps, waste, avalanche aereas, djungle in 
developing countries with insufficient traffic network etc.) 
often too much time is wasted when photograms are plotted only 
after the mission and when the plottings are brought after a 
longer period of time during a further mission to the places to 
be controlled and used. The less precise and less complete 
immediate plotting on the spot of a photogrammetric survey and 
the definitive, extensive plot effected later on, without time 
pressure, completely, more precisely and improved at the cen- 
tral services will procure remedy. 
In many cases, it would be quite sufficient to execute first 
151