1. A portable observatory. 2. An astronomical clock, made by Mr Shelton. 3. An assistant clock, made by Mr Monk. 4. A transit instrument, made by Mr Bird. 5. An astronomical quadrant, by the same excellent artist. 6. A reflecting telescope, of two feet focal length, by ditto. 7. An achromatic refracting telescope, of three and a half feet, and triple object glass, made by Mr Dollond. 8. A Hadley's sextant, by ditto. 9. Another, by Mr Ramsden. 10. An azimuth compass, by Mr Adams. 11. A pair of globes, by ditto. 12. A dipping needle, by Mr Nairne. I3. A marine barometer, by ditto. 14. A wind gage, invented by Dr Lind of Edinburgh, and made by Mr Nairne. 15. Two portable barometers, made by Mr Burton. 16. Six thermometers, by ditto. 17. A theodolite, with a level, and a Gunter's chain, by ditto. 18. An apparatus for trying the heat of the sea-water at different depths. 19. Two time-keepers, one made by Mr Larcum Kendal, on Mr Harrison's principles, and the other by Mr John Arnold. Mr Wales has particularly described some of these instruments, and the mode of using them. He has, besides, given a very interesting, though short history of the application of astronomical instruments to navigation, a summary of which, with some additional remarks, could scarcely fail to be valued by any reader concerned for the promotion of useful science. This, accordingly, it is purposed to insert whenever a proper opportunity occurs. It might seem rather a hindrance in this place.--E.