Miscellaneous articles on scientific matters, including a paper by E.M. Peligot believed to be concerning Mars; a catalogue of electrical instruments; J.C. Ward on the geology of the Lake District; examinations of Navy telescopes; plans and dimensions for telescopes; A. Krank's improved manufacture of parabolical reflectors; 'Colour correction of achromatic telescopes' by W. Harkness; 'Testing of object-glasses' by G.W. Royston-Pigott; an article titled 'Lights, beacons, and buoys', from 'The Daily News', 23 September 1879; 'physics and mathematics' by P.J. Brine, from the 'Morning Post'; 'Janssen's solar photograph and optical studies' by S.P. Langley; distortion of the Kew Photoheliograph; W.H.M. Christie's magnifying power of the half-prism; a catalogue of German instruments; J.W. Draper's new form of spectrometer; examination of sunspots and Brorsen's Comet using spectroscopic analysis by C.A. Young; and a piece in 'The Times' on oxygen in the Sun. The correspondents include C.V. Walker, C.M. Rutherford, J.H. Dallmeyer, J. Henry, E.J. Routh, G.G. Stokes, S.P. Langley, W. de W. Abney and J.W. Draper.