390 REPORT— 1873. 



Moncalieri near Turin, and by Prof. Carlo Bruno at that of Mondovi in 

 Piedmont. The curve No. 6 is the average rate of frequency per minute, 

 as given for each hour of Athens time, beginning from about 4 o'clock p.m. 

 (G. M. T), in the results of his observations of the shower by Dr. J. F. 

 Schmidt, the director of the Athens observatory. AU the curves thus shown 

 are drawn in the figure in their proper relative positions in Greenwich time. 

 The progress of the meteoric shower was intermittent, or composed of 

 alternate lulls and outbursts of the intensity of the display which almost 

 defeated attempts to count the meteors when flights of large numbers of them 

 often appeared almost simultaneously. The mode of counting adopted by 

 Professor Grant at Glasgow, and by Professor C. Bruno at Mondovi, of noting 

 the numbers visible in successive intervals of 5 minutes, fails to show the 

 rapid oscillations of intensity which took place, while it gives very distinctly 

 the gradual valuations of the shower. The method adopted by Padre Denza 

 at Moncalieri was to record the minute and second of time at the end of each 

 interval in which 400 meteors were counted, and the curve of frequency thus 

 obtained shows all the sudden oscillations of the shower*. The description 

 of its appearance by Padre Denza suggests that in the clear Italian sky more 

 remarkable features attended it than have been recorded in any other 

 meteoric shower. " Frequently small white or yellowish clouds sprang up in 

 the clear sky, and after remaining visible for a few seconds disappeared. 

 Some of these as soon as they appeared dispersed themselves in shooting- 

 stars, in general minute, but sometimes all of considerable brightness, 

 radiating towards every side like fragments from a bursting shell. The most 

 remarkable of them made its appearance suddenly near and north-west of the 

 radiant-point above Capella at 6'* 35"" p.m., in full view of the observer, Signer 

 Yergnano, without being preceded by any shooting-star. It formed a round 

 white or yellowish nebular patch of light, about 2° in diameter, in the appa- 

 rent position 71°, + 45°. It slowly drifted a short distance towards the west, 

 becoming elongated and assuming various shapes as it gradually grew fainter 

 and yellower in colour. At 6*" 50™ its position was near a and X Persii at 

 57°,-)- 53°, and it disappeared at this place at 6*" 56™ p.m., having been con- 

 stantly visible for not less than 21 minutes." Similar meteoric light clouds 

 are stated by Padre Denza to have been seen in the November star-showers 

 of 1868 and 1869 at Madrid and in the United States, and in the August 

 meteor-showers of 1867 and 1872 by the observers at Modena and Urbino ; 

 a substance of unusual tenuity in such cases perhaps entering the atmo- 

 sphere, and either emitting some denser shooting- stars at its collision, or 

 remaining luminous alon« at the point where it first encounters the upper 

 strata of the air. "A more singular appearance, not exemplified in any 

 former star-shower, took place at about 7*" 30"" p.m., during the greatest 

 intensity of the shower. A cloud of faint greyish light, like a thin veil, 

 spread itself in one instant over the wide space in Cnmclopardus between the 

 Pole-star and the Lynx, with its centre at about 55°,-|-66°, and with a 

 breadth of about 20°, hiding the faint stars in that direction. From this 

 cloud Signer Vergnano and I beheld with surprise a perfect shower of 

 meteors of the smallest size falling vertically on all sides, like the slenderest 

 serpent fireworks, differing entirely from the star-shower that occupied the 



* A process of equal-weight reduction, recommended by Mr. Glaisher, for levelling 

 very abruptly varying observations, was three times applied to the meteoric rate-curve at 

 Moncalieri before all the extraordinary oscillations which it presents were so considerably 

 removed as to produce even the very irregular curve of frequency represented on the 

 accompanying figure. 



