In the following year, that is to say on April 6, 1875, there was a total eclipse of the Sun, visible in the far East, especially Siam; but the distance from England, coupled with the very generally unfavourable weather, prevented this from being anything more than a second-class total eclipse, so to speak, although extensive preparations had been made, and the sum of £1000 had been granted by the British Government towards the expenses. A certain number of photographs were obtained, but none of any very great value. Perhaps of the next eclipse which we have to consider, it may be said that the circumstances were more varied than those of any other during the second half of the 19th century. The eclipse in question occurred on July 29, 1878. Several favourable circumstances concurred to make it a notable event. In the first place, the central line passed entirely across the United States; in other words, across a long stretch of inhabited and civilised territory, accessible from both sides to a nation well provided with the requisite scientific skill and material resources of every kind. But there was another special and rare facility available: the central line crossed the chain of the Rocky Mountains, an elevated locality, which an American writer speaks of as overhung by “skies of such limpid clearness, that on several evenings Jupiter’s satellites were seen with the naked eye.” On the summit of a certain peak, known as Pike’s Peak, a party of skilled observers, headed by Professor Langley, observed the wonderful developments of the Corona, mentioned on a previous page. The fact that such a display came under the eyes of man was no doubt mainly due to the superbly clear atmosphere through which the observations were made. That this is not a mere supposition may be inferred from the fact that at the lower elevation of only 8000 feet, instead of 14,000 feet, the Coronal streamers were seen by Professor Newcomb’s party, far less extended than Langley saw them. Perhaps the best proof of the importance of a diaphanous sky is to be found in the fact that on the summit of Pike’s Peak, the Corona remained visible for fully 4 minutes after the total phase had come to an end. A comparison of the descriptions shows that even at the elevation of 10,200 ft. the observers placed there, whilst they were better off than those at 8000 ft., assuredly did not see so much or so well as those at 14,000 ft. There occurred a total eclipse on July 11, 1880, visible in California, but as the totality lasted only 32 secs. and the Sun’s elevation was only 11°, not much was got out of this eclipse notwithstanding that it was observed in a cloudless sky at a station 6000 ft. above the sea.