The earliest proposal for igniting the bursting charges of shell by percussion appears to have been made in 1596 by Sebastian Hälle.[639] A similar proposal was made in 1610 by Graf Johann von Nassau in a MS. now in possession of the Royal Library, Berlin (MS. Germ. fol. 4), where two hand-grenades are described which explode on being let fall on the ground. The second differs from the first in having a safety apparatus to prevent premature explosions, but both are based on the same principle as Hälle’s: flints and steel so arranged as to strike together on impact with the ground.[640] In 1650 Siemienowicz gives a description (with plates) of similar grenades, without a safety arrangement,[641] which Mieth regarded as “curiosities” specially adapted to hurry those who meddled with them into the next world.[642] Yet Buchner mentions them in 1682,[643] and Anderson in 1691,[644] without any (expressed) misgivings of their danger. We may rest assured that these man-traps were never used on actual service. The use of percussion powder to ignite the bursting charges of shells was first definitely proposed, I believe, by Johann Jürgenson von Trachenfels in 1655;[645] just seven years after Glauber had drawn attention to such mixtures in his _Philosophischen Öfen_.[646] Trachenfels’ proposals were never put into practice, and no attempt was made to apply percussion powders to military purposes for more than a century. Fulminating silver, discovered by Berthollet towards the close of the eighteenth century, could not be utilised owing to the violence of its detonation. After Howard’s discovery of fulminating mercury in 1800, a number of percussion mixtures were made; but seven years passed before Rev. Alexander Forsyth proposed to use them for the priming of firearms,[647] and eleven years more elapsed before it occurred to Colonel Peter Hawker to enclose percussion priming in a copper cap.[648] The percussion musket did not make its appearance until 1842. The first English concussion fuze[649] was invented by Quartermaster Freeburn, R.A., in 1846; the first percussion fuze by Commander Moorsom, R.N., in 1850. CHAPTER XVI SIGNALS The following tables tell their own tale:— TABLE XIV. _Signal Rockets._