The authors attempt to derive some fundamental properties of the atmospheres of comets from collected photometrical quantities, primarily of classical photometric parameters.
In the first part various, currently used methods of measurements are being evalulated and some modifications or applications of them suggested. The authors point at the main insufficiencies of the methods, consisting, first of all, in the fact that the majority of them canot be cosidered as measurements in the proper meaning of that word.
In the second part the physical significance of the photometrical parameters is being theoretically interpreted. On the basis of actual material it was found that the gas-dust model of the atmospheres of comets is an acceptable explanation of the dependence of photometrical parameters on the heliocentric distance.
In the last part it has been briely demonstrated that in some cases, particularly in those of short-period comets, the alteration of the photometrical parameters with time need not be caused by change in the percentage of the meteoric dust, dispersed in the coma. The total amount of dust at the moment of observation is in comets with a continuous spectrum of the order of 10^11 g.
This following paper discusses a method for determining the total mass of dust contained in the coma of a comet. On assumption of a certain frequency distribution of particle dimensions, and based on photometrical data, it arrives at the conclusion that the maximum total quantity of dust in the atmosphere of comets at the time of observation, amounts to 8 x 10^11 g. This value appears as the result from photometric parameters of the comets, which show strong continuous spectra and are therefore by the author supposed to yield a 1 : 1 relation between the brightnesses of the dust and gas components of the coma. The photometrical measurements of Comet Arend-Roland 1956h result in a maximum value of 1.4 x 10^11 g. The photometric measurement of the anomalous tail of Comet Arend-Roland arrives at 10^13 g as the maximum value of its mass.