XLIV. Letter from M. Kreil, director of the observatory at Milan, to M. Kupffer, director general of the physical observatories in Russia, containing a succinct account of the principal results of M. Kreil's magnetic observations at Milan

1840 The London Edinburgh and Dublin Philosophical Magazine and Journal of Science  
doi:10.1080/14786444008650037 fatcat:afobdhvqrratjpav7qtfdc4wym