You are here

قراءة كتاب The proceedings of the Canadian Eclipse Party, 1869

تنويه: تعرض هنا نبذة من اول ١٠ صفحات فقط من الكتاب الالكتروني، لقراءة الكتاب كاملا اضغط على الزر “اشتر الآن"

‏اللغة: English
The proceedings of the Canadian Eclipse Party, 1869

The proceedings of the Canadian Eclipse Party, 1869

تقييمك:
0
No votes yet
المؤلف:
دار النشر: Project Gutenberg
الصفحة رقم: 4

totality, was taken, “shewing the sun’s edge cut by the peaks of the lunar mountains into irregular spots;” but these were not the Bailey Beads that I saw in Labrador, and I am confident that neither Professor Alexander nor Dr. Barnard will accept that solution. In the report of Mr. W. S. Gilman, junr., who observed the eclipse at Sioux city, Mr. Farrel gives a description and drawing of Bailey’s Beads; and what he saw in 1869, I saw in 1860, the film of light broken into rectangular pieces, which appeared to swim along the edge of the moon like drops of water.

A crowd had followed us from the town, and took a position near the observatory, as, no doubt, they thought that we would select the best place for observing the eclipse.

On the last glimpse of day-light vanishing, the crowd never fail to give expression to their feelings with a noise that is unlike anything else that I have ever heard. It is not like the noise that a crowd makes on seeing a lovely rocket burst, or that which they make on seeing some acrobat perform a wonderful feat. No; there is an expression of terror in it. It is not a shout; it is a moan.

Before giving a description of the photograms of the Total Eclipse, it will be necessary to refute some opinions that have gratuitously been given respecting them. After I had carefully examined the negatives, and made drawings, I had the drawings and the negatives compared by Mr. Langton, who expressed his opinion that they were faithful copies; and when I found that it would be many months before I could get funds to print my Report, it was agreed upon, after consulting some friends, that the negatives of totality should be sent to England. Unfortunately, I selected Mr. De la Rue as the fittest person to examine them. He never acknowledged the receipt of them, and, after many months, Mr. Falconer, who had returned to England, sent me a copy of a letter to him, from Mr. De la Rue:

“The Observatory, Cranford, Middlesex,
“Dec. 27th, 1869.

“My Dear Sir,—I am very sorry to have caused any uneasiness to Commander Ashe; but one circumstance and another have delayed my writing to him. I have received his papers, which I sent to the Astronomical, and later on, the original negatives, which arrived safely, although Commander Ashe had neglected the precaution of protecting them with a covering of glass. There is evidence in these negatives of the telescope having moved, or, perhaps, followed irregularly, during the exposure of the plates, and this renders the dealing with the negatives very difficult; moreover, it contradicts the theory set forth by Commander Ashe in respect to a certain terrace-like formation in the prominences, and also the rapid shooting out of a certain prominence. The American photographs are very much more perfect than those sent by Commander Ashe; in fact, they leave nothing to be desired. To correct the defects of duplication in Commander Ashe’s photographs, would entail some expense, [I understand that Mr. De la Rue has spent 300 pounds, in patching up Major Tennant’s photograms.] and much trouble; and it would be necessary for hint to re-write his paper.

“I have only returned to my house (after an absence of a year) a few months ago, and have had Major Tennant’s paper to see through the press; so that my correspondence has fallen greatly into arrears. Wishing you the compliments of the season, I am, with best regards,

“Yours sincerely,
“WARREN DE LA RUE.

“Alexander Pytts Falconer, Esq.,
“Bath.”

Here is a very serious charge. I am accused of foisting on the public a marvellous account of the eclipse, which my own negatives contradict; but I shall have no difficulty in shewing conclusively that Mr. De la Rue has made a blunder, when he says that “there is evidence of the telescope having moved, or, perhaps, followed irregularly.” It would have been better had Mr. De la Rue produced his evidence before he takes upon himself to assert that the negatives contradict my statements.

But the crimes I am charged with are, that on the 7th of August last, some person or persons did, accidentally or maliciously, disturb the telescope, during the exposure of plates Nos. III. and IV., and that the said plates mislead, and are not faithful representations of the phenomena seen and also, that they contradict the statements of Commander Ashe, with regard to the “rapid shooting out of a certain prominence.”

In clearing myself of these heavy charges, I shall divide my evidence into two parts—negative and positive.

In the first place, the telescope was firmly placed upon a platform made by the heavy sleepers borrowed from the railway station, and surrounded by boards, as may be seen in the photograms; and Commander Ashe has been too long at sea to travel 1398 miles with a heavy telescope, and then not to be able to give it stability. There were four persons inside the building—Mr. Falconer, seated some distance from the telescope, observing the general appearance of the eclipse with the naked eye; Mr. Stanton upon a platform, ready to uncover and cover the object-glass with a light cloth; Mr. Douglas in the dark room, and myself at the telescope, which was firmly clamped in hour-angle, and declination. The people outside were at a distance upon an elevation, and were quite still. The telescope, if it moved, must have moved in hour-angle, or declination, or in both; if it moved in hour-angle, the endless screw must have tripped upon the driving-wheel, which it could not do without making a noise, which would have been heard by me. If it moved in declination, Mr. Stanton must have moved it in uncovering the object-glass; but in so doing, he must have given the telescope a pretty hard blow, of which he must have been aware. But neither Mr. Stanton nor myself are aware of any disturbance of the telescope. There was no wind, which would only have caused a vibration, and given a blurred image. In examining Nos. I. and II. photograms, the limb of the moon may be clearly traced, and there is not a shadow of suspicion of any relative motion in the telescope. Here we have proof that the driving clock was performing its duty well for the first half of totality; and no one will have the hardihood to say that it altered its rate in the next minute and a-half. In looking at No. IV. photogram, we see that a point of light is double. Now, we will suppose this duplication was caused by the telescope receiving a smart blow; then, by drawing a line through the two positions of the same object, we get the direction of the motion. Now, look to the right and we see a protuberance with a triplicate form. Here, then, the telescope must have received two blows; and by drawing a line along the top of the three figures, we get the direction of the motion, or disturbance; and on looking at the different directions of the two motions, we see that the telescope moved two ways at once, and also, that one part of the plate was disturbed once, whilst another part of the same plate was disturbed twice—which is absurd; and lastly, Mr. Vail who had not seen the photograms when he wrote his report, gives a description of certain lines and cracks that are to be seen in the negatives when they are examined by a lens. How is it possible to get over this? Here, an American gentleman sees with a telescope exactly what is photographed. But this is negative testimony; I will now prove, conclusively, giving geometrical evidence, that Mr. De la Rue has made an egregious misstatement. The reader will have it in his power to corroborate this testimony. Place a piece of paper behind the photograms III. and IV. (taken in the principal focus), and with a needle make holes in four or five different places, taking care not to mark the bottom of a

Pages