\magnification command gives the global magnification of
the slide. As the dvi file should be magnified by the same factor,
only the quantities 1000, 1095, 1200, 1440, 1728, 2074 and 2488, resp., should
be used. A magnification factor of 1440 or 1728 will give good results, e. g.,
\magnification{1440}
Leslie Lamport has written that LATEX should not worry about a
magnification of a document. As the output device, however,
magnifies everything on the page but the sheet of paper,
it is necessary that some of the lengths for the page layout as
\textwidth have to be scaled properly.
This is done by the \magnification command.
As this procedure is hidden away from the user, he is able
to think in ``real'' dimensions. The previewing will show
a correct picture of the slide, only somehow smaller as
usually.
If the output device is not able to magnify the slide, it can be done with a photocopying machine, too. The calculation of the various lengths of the page differs as the fixed point of the mapping has changed from the offset point to the middle of the upper edge of the sheet. The eslides.sty file contains the necessary commands to handle this case.