266 



SCIENCE. 



[Vol. Y., No. 113. 



The author, a square, confesses that he is at a 

 loss what course to pursue when one of his 

 own hexagonal grandsons pleads as an excuse 

 for his disobedience that a sudden change in 

 the temperature has caused an unequal shrink- 

 ing in his perimeter, and that the blame ought 

 to be laid, not on him, but on his configuration, 

 which can only be strengthened by abundance 

 of the choicest sweet-meats. 



The women in Flatland are straight lines. 

 As they have no angles, they have no intellect ; 

 and as they have nothing to say, and no con- 

 straint of wit, sense, or reason to prevent their 

 saying it, their conversation is a great bore. 

 To such an extent has the S3'stem of female 

 non-education or quietism been pushed, that 

 they are no longer taught to read, nor to master 

 arithmetic enough to count the angles of their 

 husbands or children. The author fears that 

 this policy has been carried so far as to react 

 injuriously on the men, who are obliged to lead 

 a bi-lingual or even a bi-mental existence. 

 They must be able to speak not only the female 

 language of emotion, but also the male lan- 

 guage of science, in which ' love ' becomes ' the 

 anticipation of benefits,' 'duty' becomes 

 ' necessity ' or ' fitness,' and other words are 

 correspondingly transmuted. In the presence 

 of women, moreover, the language used implies 

 the utmost deference for their sex ; but behind 

 their backs they are both regarded and spoken 

 of as being little better than ' mindless organ- 

 isms.' The strain of this dual existence, it 

 is believed, has some tendency to enfeeble the 

 male intellect, and on that ground alone the 

 author appeals to the authorities to reconsider 

 the regulations of female education. 



LETTERS TO THE EDITOR. 



The sun-thermometer during the recent 

 eclipse. 



At mid-day, just before the commencement of 

 the eclipse, Draper's self-recording sun-thermometer 

 of this observatory indicated a sun-temperature of 

 92° F., while the self-recording thermometer in the 

 shade at the same time indicated 33° F. 



When the obscuration was at its maximum, 1.30 

 p.m., the sun-temperature had fallen to 69°, while 

 that in the shade was still 33°. 



At the end of the eclipse, 2.50 p.m., the sun-temper- 

 ature had risen to 82°, and that in the shade to 34°. 



It is interesting to note from the above facts, that 

 one-half of the difference between the sun-temper- 

 ature and that in the shade, at the beginning of the 

 eclipse, is 29|° ; while the actual fall of temperature 

 during the eclipse, as shown by the sun-instrument, 

 was 23°. This is as it should be, for only about one- 

 third of the sun was obscured. It is probable, that, if 

 the eclipse had been total, the readings of the two in- 

 struments would have been the same. 



Daniel Draper, Ph.D., Director. 



New-York meteorological observatory, 

 Central Park. 



An attempt to photograph the corona. 



It occurred to the writer that the late partial solar 

 eclipse would be an excellent chance to repeat Hug- 

 gins' s experiments on photographing the corona. A 

 three-inch refractor of about forty inches focal length 

 was employed. A drop-shutter was attached to the 

 lens, giving an exposure which was estimated at 

 about a fifth of a second. A piece of deep-violet 

 glass was procured, which could be inserted just in 

 front of the plate, or removed, at pleasure. By its 

 use a negative image of the sun's disk was obtained, 

 but without it the plate gave a reversed image ; the 

 sun being a positive and transparent, while the sur- 

 roundings remained negative and were dark, the 

 appearance being strikingly similar to that of a 

 photograph of a total solar eclipse. Both bromide 

 and chloride plates were provided; but, as with Mr. 

 Huggins, the latter proved to give much the better 

 coronal effects. A ferrous-oxalate developer was 

 employed, which contained a large proportion of 

 potassium bromide. The weather throughout the 

 eclipse was wholly favorable; and we began photo- 

 graphing at ten o'clock, two hours and twenty minutes 

 before the eclipse began, and continued at work until 

 five minutes past four, or an hour and ten minutes 

 after it had terminated. Photographs were taken 

 every half-hour, with extra ones interpolated at the 

 more interesting phases, making twenty-nine pictures 

 in all. 



Very corona-like effects were certainly produced, 

 faint rays here and there shooting out perpendicu- 

 larly to the sun's surface. But unfortunately no two 

 of the pictures were alike, and the corona in front 

 of the moon was quite as well marked as that on 

 the other side of the sun. Indeed, the most corona- 

 like ray produced, appeared in one photograph 

 stretching directly towards, and terminating at, the 

 centre of the moon. Nine photographs taken in suc- 

 cession showed one side of the halo stretching to a 

 greater distance than the other; but in one of these 

 the darkening was carried so far out, that it became 

 nearly separated from the rest of the corona, and ap- 

 peared as a distinct dark circle of the same size as, 

 and by the side of, the image of the sun. This, of 

 course, showed it to be merely an internal reflection 

 of that image, and nothing more. During the course 

 of the experiments, the object-glass was revolved 

 about its optical axis, photographs being taken in four 

 positions. No effect, however, was discernible upon 

 the plates. 



The conclusions I should draw from my experi- 

 ment are, 1°, that, though it is very easy to obtain a 

 corona-like image, one may readily be deceived in 

 such matters, and the same effect be obtained by our 

 atmosphere, without the aid of the solar corona, com- 

 bined with little defects in the gelatine film (this, 

 I think, is conclusively shown by the extension of the 

 pseudo-corona in front of the moon) ; 2°, that chloride 



