Page:Transactions NZ Institute Volume 16.djvu/35

Rh The result of the observations of the transit of 1874 cannot be regarded as satisfactory; for, whilst Sir George Airey, in his official report, stated the solar parallax as 8.76″—corresponding to 93,375,000 miles—Colonel Tupman and Mr. Stone, from the very same observations, deduced the parallax respectively as 8.81″ and 8.88″. The agreement to within the tenth of a second of arc in angular measure seems, at first sight, very close; but, so vast is the distance represented in the solar parallax by that fraction, that these three calculations differ to an extent considerably exceeding a million of miles.

The observations of the transit of Venus of last year were undertaken by all civilized nations with the same zeal and interest that characterized the efforts of 1874. On this occasion the British astronomers discarded photography, whilst the Americans relied greatly on that means of observation.

In New Zealand the egress alone could be seen, and was observed from thirteen stations by seventeen scientific gentlemen, amongst whom were Dr. Hector, Mr. McKerrow, and Archdeacon Stock. There were also an English party of observers, near Christchurch, under Colonel Tupman, and an American party at Auckland, under Mr. Edward Smith, of the United States Coast Survey. The Government assisted liberally both by grants of money and by placing the Telegraph Department at the disposal of the observers. Unfortunately, Dr. Hector's observation at Clyde was partially intercepted by a cloud, but, with the exception of this contretemps, the observations in New Zealand were entirely successful. I cannot but remark that it reflects great credit on the colony that so many gentlemen should have voluntarily engaged in this work; and I have no doubt that, when the report of the results of the British expeditions are published, their services will receive cordial acknowledgment.

The observations of last year's transit throughout the world were attended with thorough success, and it is expected that, when the calculations have been completed, a great step will be made towards reconciling the conflicting results that have hitherto been obtained. But, before the question can be finally set at rest, the results of the observations on the transit of Venus must be reconciled with those obtained by other methods, which it would be out of place for me now to discuss.

Judging, however, from the conclusions already derived from various independent calculations, it seems probable that the true distance of the earth from the sun will be found to be between ninety-two and ninety-three millions of miles.

Meanwhile the scientific world awaits with the greatest interest the calculations of astronomers on this vital problem. The importance of it is not merely to be regarded as one which concerns