286 
EASTMAN. 
In the same paper Professor Newton estimates the whole 
number of meteors in the August ring as 300,000,000,000,000. 
In March, 1862, A. C. Tivining l , published a paper entitled 
“ Investigations respecting the phenomena of meteoric rings 
as affected by the earth,” and arrived at the following con¬ 
clusions : “ The position of the node of the ring cannot be 
shifted by the earth’s action more than a degree or two in 
half a million of years; there is an appreciable change of 
radiant positions, relative to locality on the earth’s surface 
and to the hour of the day, whose maximum is about 3 j° be¬ 
tween the extremes and to which the extremes approach ; the 
terrestrial disturbance is sufficient to affect the perihelion 
distance of the meteors by many millions of miles and to 
expand the ring to a corresponding breadth at' the ascend¬ 
ing node; also to collect together in orbits, of similar ele¬ 
ments, those meteors which are similarly affected in respect 
of radiant positions; and terrestrial disturbances do not ap¬ 
pear sufficient to draw off meteors into permanently erratic 
orbits; so that, unless in exceptional instances, meteors are 
not lost to the ring other than those which the atmosphere 
absorbs or arrests. If meteors are partially arrested without 
being dissipated in an excessively tenuous upper medium 
it may be possible that the ordinary and unconformable 
meteors are such as have missed a return to the ring under 
the effect of atmospheric retardation.” 
Mr. Twining appends the suggestion that, “ perhaps comets 
whose vastly extended atmospheres or heads around the 
nucleus, although greatly attenuated are perhaps competent 
to arrest meteors completely, may be found in rare instances 
to have been disturbed by impact with a meteoric ring whose 
mere attractive influence it would not be possible to detect.” 
In 1863, Mr. B. V. Marsh, 2 of Philadelphia, published a 
paper on “ The luminosity of meteors as affected by latent 
heat,” in which he arrived at the following results: “ The 
upper regions of the atmosphere, even to its utmost limit, 
1 A. J. S., XXXIII 2 , 244. 
2 A. J. S., XXXVI 2 , 92. 
