NATURAL HISTORY NOTES 
37 
grievously misunderstand his remarks) started on his study of meteorites as an 
unbeliever, and only convinced himself of their ultra-terrestrial origin after patient 
investigation. 
Your correspondent considers it an extraordinary circumstance that meteorites, 
if they fall from the sky, do not fall down upon human beings, animals, houses, 
&c. , or on roads or pavements ; but has he taken into account the very small area 
occupied by living creatures, buildings, &c., as compared with the total extent of 
the earth’s surface ? Hut damage to property is in some cases reported, and, 
according to Humboldt, at least four persons have been struck dead by stones 
falling from heaven. 
Mr. Ilastie is justified in citing the authority of Sir Robert Ball as to the 
ultimate origin of those meteoric stones being terrestrial and volcanic. I do not, 
however, understand Sir Robert Bill as putting forward this view as a completely 
satisfactory hypothesis, but as the least improbable of the many theories which 
have been advanced, all of which he regards as open to objec ion. This is, I 
must admit, equivalent to a definite pronouncement against the theory of celestial 
origin, and coining from such an eminent authority it is enlilled to the highest 
respect, but I have not the advantage of knowing the reasons which have led him 
to this opinion. Sir Robert has himself brought vividly before our mind’s eye the 
millions of orbs in the interstellar spaces which our natural eyes cannot see, 
simply because they do not, like the visible stars, send out light ; and he has 
demonstrated in a masterly manner the effects resulting from a collision between 
two of these dark bodies, an occurrence of whi~h we had an ocular example not 
very many months ago. It is admitted that the shooting stars have, previously to 
their appearance as such, had their own paths in ultra-terrestrial space, and many 
of these cannot be identified wiih known cometary or other swarms. Where 
then is the difficulty of believing that there may exist in space bodies of an 
intermediate order between these two classes, large enough to pierce the earth’s 
atmosphere and reach its surface, yet not so massive as to cause serious damage to 
our planet ? 
With respect to the gunnery experiments, it is of course true that the force of 
gravity, which is adverse in the case of a projectile, would be in favour of a body 
approaching the earth from space ; but from what we know of planetary velocities 
I think gravity would be a very unimportant factor in the problem. In any case 
the resistance of the air, as an imperfectly fluid medium, to a body moving at such 
a velocity, mu-t be enormous, and whatever tended to increase the velocity would, 
once the atmosphere were entered, also lead to increase of the resistance, and 
consequently the retardation. 
The volcanic theory certainly derives some force from the discovery that some 
masses of native iron, such as the Ovipak, and those found in New Zealand, 
formerly supposed to be volcanic, are probably telluric ; but I think this would 
only apply in volcanic distiicls. It is easy to understand that a smelting process 
might take place in the great heat of an active volcano ; but with regard to the 
products of volcanoes which may have existed “many ages ago in the world’s 
history,” would a substance so susceptible to chemical action as iron retain its 
metallic character throughout those ages? Would it not (assuming that it has 
remained in contact with the earth, and not in the meantime been projected into 
space), have been long ago completely oxidised, sulphuretted, or otherwise con- 
verted into ore ? 
As regards the lightning theory, it should be noticed that on several occa- 
sions on which a meteoric stone has been seen to fall it is distinctly stated that 
the sky was at the time clear. This circumstance, coupled with the fact that 
before the nature of lightning was generally understood such stones were by many 
thought to be “thunderbolts,” may have given rise to the familiar expression “a 
bolt from the blue.” 
Mr. Ilastie asks on what theory it is that meteoric stones, as it is said, explode 
just at the very time that they get very' near to the earth’s surface. I think lie 
must have misunderstood what has been said in this respect. I do not suppose 
any one believes that meteors explode at any particular distance, near or far, from 
the ground. The obvious explanation is that they explode when they have 
acquired sufficient heat, through retardation, to produce a disruptive effect. 
This may happen in a higher and rarer, or lower and denser, stratum of the 
