"Intersection of the Orbits of Mars and certain Asteroids. 335 
Arr. XXXVI.—On the possible Intersection of the orbits of Mars 
and certain of the Asteroids; by Professor DANIEL KIRKWOOD, 
of the Indiana University. 
THE present eccentricities of the asteroidal orbits are included 
between the limits 0-046085 and 0°336987. Of these, some are 
v 
increasing, others diminishing. We are not aware, 
that the range of variation has, in any instance, been accurately 
determined. If we assume the superior limit of the eccentricity, 
in the case of the following members of the group, to be 025, 
tnd this is less than the present eccentricity of Juno, Phocea, 
Polyhymnia, and Atalanta,) their perihelion distances at the 
chs of maximum eccentricity will be as follows: 
Flora, ..., 1°650940 
Ariadne, bt 1652879 
Harmonia, ......... 1700861 
Melpomene,...,. 1°722045. 
The present aphelion distance of Mars is 1°665725, the eccen- 
Meity of the Martial orbit is, however, increasing; the secular 
Yaniation being 0000090176, According to LeVerrier the maxi- 
ists eccentricity will be 0-14224. The corresponding aphelion 
nee will be 1°740481; greater than the least perihelion dis- 
tht 3 of the asteroids above named. It is obvious therefore 
ped if the longitudes of Mars and any one of these bodies 
a Id differ by nearly 180° when the eccentricities of both are 
tot far from their superior limits, the orbits or at least their pro- 
‘Hons on the plane of the ecliptic, must intersect. When it is 
a. red that the variation of the eccentricity is extremely 
revol that the line of apsides of the orbit of Mars completes a 
the ution in less than 20,000 years, aud that the inclinations of 
abilits its of Flora, Harmonia and Ariadne, are small, the prob- 
ty of a very near approach of Mars and some of these small 
Derturbatiar approach so close as to render the question of the 
“ae ions of the latter both curious and interesting—is at 
in patent. If we assume the greatest eccentricity now found 
texime P88 the superior limit of the variation of all, the 
init *Phelion distance of Mars will be greater than the 
im perihelion distances of twenty of the small planets. — 
: Ind, Feb. i, 1859. 
