Dr. Nagy I. Zoltán szerk.: Fragmenta Mineralogica Et Palaentologica 6. 1975. (Budapest, 1975)

ting into the terrestrial atmosphere and frictional heating is experienced, its surface may be heated even to 1200 or 2000 degrees centigrade. The red-hot and later incandescent white outer shell of the meteoric body is gradually separating from the inner core which remains in an invariably cold state. Lather the deformed incandescent shell is unable to counterbalance the stress by elastic forces, it suffers fissures it breaks down, and its fragments are flying away. The separation of the fragments of the shell from the main mass of the body is taking place under violent jerkesandthe presence of this force, as well as the loss of mass are disturbing the existing state of equilibrium and the meteoric masses are tending toward another state of equilibrium. However, this process is repeating itself almost at every moment, and thus the meteor is experiencing an accelerating and irregular fluctuating motion, conserving, however, as a consequence of its inertia, its path along a straight line. Concerning the time which elapsed from the first explosion until the hitting of the ground by the last fragment, we computed probable duration of 4, 5 to 5,0 sec. SZABÓ is stating correctly, that "this whole sequence of events (i.e. from the appearance of the phenomenon at Liptószentmiklós until the hitting of the ground by the last fragment of 295 kgs) occured within a few seconds." A probable value for the translation velocity of the meteor in its path can be determined on the basis of the assumption that its altitude at the time of its appearance should have been (according to earlier experience) about 200 kilometres and the projection of itspath had a length of 212,3 kilometres. The real path has, however, a length of 292 kilometres and this path was covered in 4, 5 to 5,0 sec. Thus, its velocity was 65 km/sec, a velocity which has decreased only in the near-the-ground atmospheric layers, that is, within the last few kilometres of the path (RÓKA 1963). The fragment weighing 294 kgs of the Knahina meteor penetrated, in spite of its enormous velocity, only to a depth of 3, 5 metres into the soil. This may be explained by the fact that soil is exerting against every penetrating body a very high resistance. In the course of my studies in the field of vulcanology (as early as in 1932) some experts of the Institute of Military Engineering were kind enough to consider for me the following situation: if, from an active volcano, a basaltic bomb of the weght of 1000 kgs and of the shape of a citron, with a sharp regular end, would be projected to a very great height, say, to the 1000 metre level, its falling back into a loose Pannonian sand soil would be causing no larger penetration than one of 3 or 4 metres. Thus, the biggest meteorite of Knahina is not only that one which penetrated to the largest depth among all the known meteorites, but even the meteorites and volcanic bombs possessing much greater weight respectively masses are unable to penetrate to greater depths. However, it should be noted, that this big fragment fell not vertically but it arrived from the W and digged for himself a channel of about 90 metres in length with a slope angle of 2°14' and came finally to rest in the depth of 11 feet, that is of 3, 5 metres. The enormous velocity, with which the meteors are penetrating into the atmosphere, is quite rapidly reduced by air resistance. In the vicinity of the terrestrial surface, meteorites are arriving at most with a velocity of several hundreds of m/sec. Their final velocities are, accordingly, not higher than those of artillery projectiles, and they are