Page:The story of the comets.djvu/121

VI. The comets in this group are all recent discoveries, but as none of them have been seen more than once their claims to be regarded as permanently attached members of the solar system must be regarded as in suspense for the present.

On July 16, 1884, E. E. Barnard, at Nashville, Tennessee, U.S., using a. 6-inch refractor, discovered a nebulous object which he thought had a suspicious appearance. Some days however elapsed ere its cometary character was ascertained beyond a doubt, by reason of it being found to be moving. Perrotin described it as exhibiting on Aug. 15, an ill-defined nebulosity about 1$1⁄2$' in diameter. The ellipticity of the orbit was soon ascertained. If Berberich's period of 5⋅49 years is correct the comet must have approached very near to Mars in April 1868, and have had its orbit interfered with by that planet.

This comet should have returned in 1889, but was missed in that year, and again also in June 1895. It was also missed in Oct. 1900, though about the time it was expected 25 photographs were taken over a range of sky covering the comet's expected position. Nor was it seen in 1906. Whether this comet should be transferred to the list of "lost" comets remains for future consideration.

This comet was discovered by Brooks on May 22, 1886. It passed its perihelion on June 6. A period of 6⋅3 years was assigned to it. It was not seen when expected in 1892, 1899, and 1903, and therefore its continued existence must be regarded as an unknown quantity. We must see what the years 1909 and 1910 bring forth.

The circumstances under which this comet was discovered by means of a photograph on Oct. 12, 1892, have already been mentioned. Suffice it to say here that a period of