File:Transactions and proceedings of the New Zealand Institute (1873) (14564863697).jpg

Identifier: transactionsproc61873newz (find matches)
Title: Transactions and proceedings of the New Zealand Institute
Year: 1868 (1860s)
Authors: New Zealand Institute (Wellington, N.Z
Subjects: Science Birds
Publisher: Wellington : J. Hughes, Printer
Contributing Library: Smithsonian Libraries
Digitizing Sponsor: Biodiversity Heritage Library

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he moons semi-diameter,Avhich, beaiing a fixed proportion to the horizontal parallax, may be markedoff on each cardboard ellipse, and it is the work of a minute to see the momentat which the ingress and egress occurs, and the point on the moons perimeterat which the star enters and emerges. It is obvious that the same process isequally applicable to solar eclipses, taking of course the differences of theirparallaxes and motions and the sum of their semi-diameters. Now that binocular telescopes are so largely used, and are made to powers soconsiderable as 7 or 8 diameters, the observation of a star of fourth magnitudeentering on the dark limb of the moon—that is before the full—may be perfectlywell observed on board ships, and, I believe, in clear weather fifth magnitudestars could be seen; and, as one observation will give a longitude thoroughlytrustworthy within very narrow limits, it seems a pity that they should soseldom be used. Tirans.N. Z .Ins t .Yol .VI. PI .VI \-, r y T* P
Text Appearing After Image:
ia.Ho)lLck,a.el.<jblitiL. Wife 8t&-Co imp. Heale.— On Moon Occultations. 61 I have heie the computations of five occultations -which I have observedwith a portable telescope at different times without any special care. Of thesefour agree with one another within a maximum of seven seconds ; the fifth isapparently affected by some blunder, as it varies upwards of twenty secondsfrom the others, but, as even this discrepancy is only about four and a-halfstatute miles, it might be considered accurate in comparison with theapproximations generally available on board ship. The calculation of longitude from the observations is, it will be observed,not by any means formidable for its length, and it presents no intricacieswhich an ordinary navigator may not easily master. II.—ZOOLOGY. AuT. XII.—On Harpagornis, an Extinct Genus of Gigantic Raptorial Birds of New Zealand, By Julius Haast, Ph.D., F.RS., Director of the Canterbury Museum. \_Read heforz the Philosophical Institute of Ca

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