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The Astrophysical journal . ^^-^44-^^^!. 196 H. C. LORD i, = c rA-,(2a/{. (3) 2ttR(twhere 4o = r— • This integral cannot be obtained directly. Wadsworth evalu-ated by mechanical quadrature. This can be done much moreeasily and rapidly by means of the planimeter as follows: theordinate of the curve (3) at any point t is evidently proportionalto that portion of the curve (2) included between the ordinateswhose abscissae are K—l^o ^^^ ^ + 2^0 I^ence in order to plotthe curve (3) it is only necessary to measure with a planimeterthe area above specified and draw an ordinate at the point ^ pro-porti
The Astrophysical journal . ^^-^44-^^^!. 196 H. C. LORD i, = c rA-,(2a/{. (3) 2ttR(twhere 4o = r— • This integral cannot be obtained directly. Wadsworth evalu-ated by mechanical quadrature. This can be done much moreeasily and rapidly by means of the planimeter as follows: theordinate of the curve (3) at any point t is evidently proportionalto that portion of the curve (2) included between the ordinateswhose abscissae are K—l^o ^^^ ^ + 2^0 I^ence in order to plotthe curve (3) it is only necessary to measure with a planimeterthe area above specified and draw an ordinate at the point ^ pro-portional to this area. In practice it is convenient to take asunity the area between the ordinates at 0 — ^^^ and 0 + 4^^ asthis gives the intensities in terms of the intensity at the the absence of the planimeter, if the several curves be drawnon cross-section paper the areas can be obtained b}- counting thenumber of squares included between any two ordinates. Forexample, a slit whose width is mm at the focus of a c
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectspectru, bookyear1895