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it is necessary to solve a more or less complicated system of equations, but much labor may be saved by the use of the so-called "Besselian Elements," which are tabulated in most National Ephemerides. These tables give the coördinates of the center of the moon's shadow and the radii of the umbra and penumbra on the fundamental plane, also the direction of the axis of the shadow with respect to the same plane. The Besselian Elements will be found convenient for many purposes, and have been used throughout our calculations. Unless otherwise stated, the times given are Greenwich, the first hour commencing at midnight, that is, midnight is either numbered 0 or 24.

For the earth generally, the eclipse begins at 3h 59m and ends at 9h 14m. The Central Eclipse begins at 4h 55m in east longitude 21° 09′ and north latitude 6° 52′ and ends in east longitude 141° 58′ and north latitude 14° 28' at 8h 18m. The sun will be on the meridian at 6h 38m in east longitude 82° 45', and south latitude 10° 05'. The axis of the umbra first touches the surface of the earth at a point 33° 47′ east and 3° 07' north, that is, in Central Africa. After leaving the coast of Africa the center of the shadow moves east over the Indian Ocean and will not touch land again until about 7h 35m.8, when it sweeps at a rate of 1388 miles per hour at a point approximately 102° 18' east and 4° 0′ south, on the west coast of Sumatra. The locus of the center of the shadow will run approximately 15 miles south of Benkoelen, and the width of the zone of totality in that region will be about 89 miles. Thence the shadow passes with increasing velocity over Sumatra, Banka, Borneo and Mindanao, finally leaving the earth's surface at a point 129° 24' east and 10° 44′ north.

Chart 1 has been prepared for the purpose of assisting those who desire to obtain, with reasonable accuracy, the times of the several contacts and other information, without rigorous computations for the particular localities in which they happen to be situated. The chart shows the locus of the shadow over the Netherlands East Indies, the outline of the advancing and receding edge of the moon's shadow every ten minutes of time, and also the position angle of the first point of contact. To illustrate the use of this chart, let us attempt to find the times of the beginning and ending of the partial eclipse which will be visible from Batavia. Upon examining this chart it will be found that Batavia lies between the 6h 10m and 6h 20m beginning lines, which are indicated in full lines; to be more exact it is 0.58 of the distance. Therefore we have to add 5m.8 to 6h 10m to obtain the instant of first contact, which gives us 6h 15m.8. A rigorous computation actually gives 6h 15.5. Similarly, for the ending, Batavia lies 0.74 of the distance between the 8h 50m and 9h 0m ending lines, which are shown on the chart as broken lines. Thus we obtain 8h 50m+7m.48h 57m.4 for the ending of the eclipse. Actually it should be 8h 57m.6. Lines have been drawn across the shadow path, which give the times of mid-eclipse, while the duration of the total phase is indicated on the chart near by.. Suppose, for instance, that one desires to, obtain the



time of mid-eclipse and duration of totality at Palembang, which is to all intents and purposes on the center line. Palembang is 0.11 of

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the distance between the 7h 40m and 7h 50m lines described above, and the time of mid-eclipse will therefore be 7h 41m.1. The duration will be 3m 140.11 (3m 14-2m 56%) which equals 3m 12s. Palembang


is, in fact, a little south of the center line, so, as we shall see later, the
duration should be slightly less than this value; actually it is 3m 78.

If the place about which we desire information lies within the
shadow zone but is not actually on the center line, then the duration of
totality will be shortened.

The lines running across the outlines of the advancing edge of the moon's shadow give the position angle of the first point of contact, which is, of course, measured from north through east in anti-clockwise direction. For instance, at Padang, it will be seen that the first point. of contact will occur at 251°.

For the more important places in the Archipelago the astronomical data have been rigorously computed and are given in Table I.

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- 058 1

h m

6 018 251
6 330


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Figure 1 illustrates the appearance of the phenomenon as it will be seen from Batavia. The moon is shown in three positions, namely, at 6h 15.5 when the eclipse will commence, at 7h 37m.0 when the eclipse will reach a maximum, and again, at 8h 57m.6 which marks the end of the eclipse. On the moon's path will be found a scale of time, and to obtain a picture of the eclipse at any instant, all that is necessary is to place the point of a compass on the scale at the time desired and then describe a circle of radius equal to that already drawn to represent the moon.

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* Contact

Figure 2 gives the fiducial lines for observing stations on the center line in the vicinity of Benkoelen. They will be found helpful in setting spectrographs and other instruments.

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From an astronomical point of view it will be seen that the best position to make observations is about 15 miles south of Benkoelen, along the main automobile road to the village of Tais, where the duration of the total phase will be about 3m 20s; but before entertaining such an idea we should consider the accessibility of this place and examine the all important climatological conditions which are to be expected along the path of the eclipse during the month of January.

The climatological conditions along the shadow path are more or less an unknown quantity, for the reason that the majority of the islands in the Netherlands East Indies are covered with primeval jungle, swamps and prairies of tall coarse grass, into which present day civilization has not penetrated to any great extent. The high mountain ranges traversing the various islands strongly affect the climate in various ways, and on this account a general description of the climatological conditions is difficult. The relative situation of the islands to the continents of Asia and Australia is perhaps the greatest factor in determining the climatic conditions found in them. Owing to the disposition of these large land masses, the northwest and southeast monsoon winds blow steadily during alternate seasons. These winds regulate the localization of the rainfall to a very large extent, and there are accordingly well marked wet and dry seasons. The average daily temperature on the coast is about 80° Fahrenheit and the night temperature about 70°; and it may be remarked that this state of affairs is extraordinarily equable. In general, the climate on the coast and in the lowlands is very damp, and the temperature sometimes, but very rarely, rises over 98°.5 F. In contrast, however, in some of the

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