Monthly Notices of the Royal Astronomical Society Volume . 33 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1873 Excerpt: ...keep the equator to the southward in the centre of the sphere of vision, to count the number of shooting stars that appeared during the whole period of observation, to delineate on star-charts as many as possible of the tracks, and to enter in a note-book the time by chronometer, colour, estimated duration, magnitude, &c. In this manner 3800 meteors were observed on 154 mornings free from moon or cloud, the average duration of an observation being a little over two hours. 2000 tracks were registered, and from these the radiant positions were deduced, the other 1800 telling in the horary numbers and richness of streams. In order to carry out these observations, I found it necessary to construct star-charts on purpose, of fine London board, on which the stars were represented with common ink. No printed charts would bear the continual erasure of the pencil-marks. Since only the equatorial regions were required, I chose the cylindrical projection on a scale of io of R.A. to the inch, and inserted all the stars in the Astronomical Society's Catalogue down to the sixth magnitude inclusive, the lines of R.A. and declination being drawn in a colour that was invisible by ordinary lamp-light. For observations of the great August stream, I used a copy of Plate XI. of the British Association Gnomonic Atlas for 1868. The epoch of the Perseus Radiants is therefore 1850, of the others 1830. From the necessity of clearing off the tracks every second or third day (and sometimes every day), doubtless many poor streams escaped detection. The complete reduction of such a mass of observations would require more time than I can devote to it, while I think very little would be found to repay the labour. Most of the streams would be a little enriched, a few new ones discovere...