Eclipses of the Moon in India

niin, Tables drawn up by Dr. Robert Schranl for determining questions conilectcd with eclipses of the sun in India for a period of 1600 years. The eclipses of the moon arc now dealt with, and a few notes added. I dcsirc to express my best thanks for their kind advice and assistance to Professor H. 1.1. Turner, of Oxford, and Mr. A. C. D. Crommelin, of the Royal Observatory, Greenrvich. Pandit ahkara Hilkrishna Uikshit, whew dcath early in the present year is greatly to be deplored, rcidcred valuable help by checkrilg iny figures. ECLIPSES OF THE MOON IN INDIA BY RORERT SEWELL. INTRODUCTION, RCI,ES, AND EXAAIPLES. TIIE following Tables will be found to contain all that is necessary for the deterniiilatioi of the actual time of occurrence of eclipses of the moon for thc period of sixteen hundred years, from A.D. 300 to rgoo. The calclations in Table E. have been based on von Oppolzers Cmws der Fi,rsiernLr.re Deakschrzyea de Matkeatisch WLUYZWSSEZ chaftlichev CUSSE du Kois. Akadcmie rtpr tViSSezchaften iz I.Vdex, Vol. LU., I 887. All eclipscs are included, whethcr visible or invisible. Visibility at a given spot, if not apparcnt on the facc of Table E., must be tested according to the rules hereinafter given. The results obtained will be closely approximate, but are liable to small errors of a minute or two, owing to minor inequalities in the moons motion w11icl1 have been left out of account by Oppolzcr. Table G. also is sinilarly liable to slight varialions, for reasons which will be noted below. Absolute exactness is impossible under the circumstances, and it would be uselcss to attempt morc than is given in this volunie. A comparison between the times fixed by Oppolzers Canon and by the Naatacok Alnazaclcs since the year 1767 sfe Table H. will shew how even the most reliable authorities differ in their calculalions. A lunar eclipse is visible in the same degree on every part of the earths surface which, during any part of its occurrence, is turned away from the sun and towards the moon-then at the full and on the other side ol the earth or, in other words and speaking broadly, on ally meridian bctlveen the hours of sunset ald sunrise. For Indian purposes, therefore, the calculations for these tabIcs havc been made for the meridian of Ladka Ujjain, Fe. Greenwich East Longitude 75 4Gf, and the necessary time-correction, 5 h. 3 m., has been applied to the Canoa figures which were prepared for the meridian of Greenwich. All times are measured from mean sunrisc at Lalika, talccn as 6 A.M. Von Oppolrer calculated every eclipse in apparent time and then, for civil purposes, changed this to mean- or clock-time for the meridian of Greenwich by applying the daiIy cquation of time. The tables in the present volume give similar mean time for the meridian of Laitka. No account has been taken of the effect produced on the moon by the penumbra, but z THE IATDIAN CALENDAR. only of er passage across the cone of complete shadow. In actual observation iittlc change is witnessed until the phenomenon of positive occultation, or positive alteration of the shape of the iIIuminated sufitce, takes place. Moreover 1 am assurcd by Pandit a6kara Bilkfislna Dfkhit that in Hindu astrolomical rvorks only the latter is taken into account. The dates given in Col. I of Table E. will sometimes be found to be ollc day behind those given in the Crrzon... --This text refers to an alternate Paperback edition.