___________________________________________________________ | | | | | t. | 760x(1+dt). | t. | 760x(1+dt). | t. | 760x(1+dt). _____|_____________|_____|_____________|_____|_____________ | | | | | °C. | | °C. | | °C. | 0.0 | 750.000 | 1.7 | 764.7352 | 3.4 | 769.4704 .1 | 760.2785 | .8 | 765.0137 | .5 | 769.7489 .2 | 760.5571 | .9 | 765.2923 | .6 | 770.0274 .3 | 760.8356 | 2.0 | 765.5708 | .7 | 770.3060 .4 | 761.1142 | .1 | 765.8493 | .8 | 770.5845 .5 | 761.3927 | .2 | 766.1279 | .9 | 770.8631 .6 | 761.6712 | .3 | 766.4064 | 4.0 | 771.1416 .7 | 761.9498 | .4 | 766.6850 | .1 | 771.4201 .8 | 762.2283 | .5 | 766.9635 | .2 | 771.6987 .9 | 762.5069 | .6 | 767.2420 | .3 | 771.9772 1.0 | 762.7854 | .7 | 767.5206 | .4 | 772.2558 .1 | 763.0639 | .8 | 767.7991 | .5 | 772.5343 .2 | 763.3425 | .9 | 768.0777 | .6 | 772.8128 .3 | 763.6210 | 3.0 | 768.3562 | .7 | 773.0914 .4 | 763.8996 | .1 | 768.6347 | .8 | 773.3699 .5 | 764.1781 | .2 | 768.9133 | .9 | 773.6485 .6 | 764.4566 | .3 | 769.1918 | 5.0 | 773.9270 _____|_____________|_____|_____________|_____|_____________ ___________________________________________________________ | | | | | t. | 760x(1+dt). | t. | 760x(1+dt). | t. | 760x(1+dt). _____|_____________|_____|_____________|_____|_____________ | | | | | °C. | | °C. | | °C. | 5.1 | 774.2055 | .9 | 787.5755 | .7 | 800.9454 .2 | 774.4841 |10.0 | 787.8540 | .8 | 801.2239 .3 | 774.7626 | .1 | 788.1325 | .9 | 801.5025 .4 | 775.0412 | .2 | 788.4111 |15.0 | 801.7810 .5 | 775.3197 | .3 | 788.6896 | .1 | 802.0595 .6 | 775.5982 | .4 | 788.9682 | .2 | 802.3381 .7 | 775.8768 | .5 | 789.2467 | .3 | 802.6166 .8 | 776.1553 | .6 | 789.5252 | .4 | 802.8952 .9 | 776.4339 | .7 | 789.8038 | .5 | 803.1737 6.0 | 776.7124 | .8 | 790.0823 | .6 | 803.4522 .1 | 776.9909 | .9 | 790.3609 | .7 | 803.7308 .2 | 777.2695 |11.0 | 790.6394 | .8 | 804.0093 .3 | 777.5480 | .1 | 790.9179 | .9 | 804.2879 .4 | 777.8266 | .2 | 791.1965 |16.0 | 804.5664 .5 | 778.1051 | .3 | 791.4750 | .1 | 804.8449 .6 | 778.3836 | .4 | 791.7536 | .2 | 805.1235 .7 | 778.6622 | .5 | 792.0321 | .3 | 805.4020 .8 | 778.9407 | .6 | 792.3106 | .4 | 805.6806 .9 | 779.2193 | .7 | 792.5892 | .5 | 805.9591 7.0 | 779.4978 | .8 | 792.8677 | .6 | 806.2376 .1 | 779.7763 | .9 | 793.1463 | .7 | 806.5162 .2 | 780.0549 |12.0 | 793.4248 | .8 | 806.7947 .3 | 780.3334 | .1 | 793.7033 | .9 | 807.0733 .4 | 780.6120 | .2 | 793.9819 |17.0 | 807.3518 .5 | 780.8905 | .3 | 794.2604 | .1 | 807.6303 .6 | 781.1690 | .4 | 794.5390 | .2 | 807.9089 .7 | 781.4476 | .5 | 794.8175 | .3 | 808.1874 .8 | 781.7261 | .6 | 795.0960 | .4 | 808.4660 .9 | 782.0047 | .7 | 795.3746 | .5 | 808.7445 8.0 | 782.2832 | .8 | 795.6531 | .6 | 809.0230 .1 | 782.5617 | .9 | 795.9317 | .7 | 809.3016 .2 | 782.8403 |13.0 | 796.2102 | .8 | 809.5801 .3 | 783.1188 | .1 | 796.4887 | .9 | 809.8587 .4 | 783.3974 | .2 | 796.7673 |18.0 | 810.1372 .5 | 783.6959 | .3 | 797.0458 | .1 | 810.4175 .6 | 783.9544 | .4 | 797.3244 | .2 | 810.6943 .7 | 784.2330 | .5 | 797.6029 | .3 | 810.9728 .8 | 784.5115 | .6 | 797.8814 | .4 | 811.2514 .9 | 784.7901 | .7 | 798.1600 | .5 | 811.5299 9.0 | 785.0686 | .8 | 798.4385 | .6 | 811.8084 .1 | 785.3471 | .9 | 798.7171 | .7 | 812.0870 .2 | 785.6257 |14.0 | 798.9956 | .8 | 812.3655 .3 | 785.9042 | .1 | 799.2741 | .9 | 812.6441 .4 | 786.1828 | .2 | 799.5527 |19.0 | 812.9226 .5 | 786.4613 | .3 | 799.8312 | .1 | 813.2011 .6 | 786.7398 | .4 | 800.1098 | .2 | 813.4797 .7 | 787.0184 | .5 | 800.3883 | .3 | 813.7582 .8 | 787.2969 | .6 | 800.6668 | .4 | 814.0368 _____|_____________|_____|_____________|_____|_____________ ___________________________________________________________ | | | | | t. | 760x(1+dt). | t. | 760x(1+dt). | t. | 760x(1+dt). _____|_____________|_____|_____________|_____|_____________ | | | | | °C. | | °C. | | °C. | 19.5 | 814.3153 |23.0 | 824.0642 | .5 | 833.8131 .6 | 814.5938 | .1 | 824.3427 | .6 | 834.0916 .7 | 814.8724 | .2 | 824.6213 | .7 | 834.3702 .8 | 815.1500 | .3 | 824.8998 | .8 | 834.6487 .9 | 815.4925 | .4 | 825.1784 | .9 | 834.9273 20.0 | 815.7080 | .5 | 825.4569 |27.0 | 835.2058 .1 | 815.9865 | .6 | 825.7354 | .1 | 835.4843 .2 | 816.2651 | .7 | 826.0140 | .2 | 835.7629 .3 | 816.5436 | .8 | 826.2925 | .3 | 836.0414 .4 | 816.8222 | .9 | 826.5711 | .4 | 836.3200 .5 | 817.1007 |24.0 | 826.8496 | .5 | 836.5985 .6 | 817.3792 | .1 | 827.1281 | .6 | 836.8770 .7 | 817.6578 | .2 | 827.4067 | .7 | 837.1556 .8 | 817.9363 | .3 | 827.6852 | .8 | 837.4341 .9 | 818.2149 | .4 | 827.9638 | .9 | 837.7127 21.0 | 818.4934 | .5 | 828.2423 |28.0 | 837.9912 .1 | 818.7719 | .6 | 828.5208 | .1 | 838.2697 .2 | 819.0505 | .7 | 828.7994 | .2 | 838.5483 .3 | 819.3290 | .8 | 829.0779 | .3 | 838.8268 .4 | 819.6076 | .9 | 829.3565 | .4 | 839.1054 .5 | 819.8861 |25.0 | 829.6350 | .5 | 839.3839 .6 | 820.1646 | .1 | 829.9135 | .6 | 839.6624 .7 | 820.4432 | .2 | 830.1921 | .7 | 839.9410 .8 | 820.7217 | .3 | 830.4706 | .8 | 840.2195 .9 | 821.0003 | .4 | 830.7492 | .9 | 840.4981 22.0 | 821.2788 | .5 | 831.0277 |29.0 | 840.7766 .1 | 821.5573 | .6 | 831.3062 | .1 | 841.0551 .2 | 821.8859 | .7 | 831.5848 | .2 | 841.3337 .3 | 822.1144 | .8 | 831.8633 | .3 | 841.6122 .4 | 822.3930 | .9 | 832.1419 | .4 | 841.8908 .5 | 822.6715 |26.0 | 832.4204 | .5 | 842.1693 .6 | 822.9500 | .1 | 832.6989 | .6 | 842.4478 .7 | 823.2286 | .2 | 832.9775 | .7 | 842.7264 .8 | 823.5071 | .3 | 833.2560 | .8 | 843.0049 .9 | 823.7857 | .4 | 833.5346 | .9 | 843.2835 | | | |30.0 | 843.5620 _____|_____________|_____|_____________|_____|_____________
CHAPTER VIII.
FIRING POINT OF EXPLOSIVES, HEAT TESTS, &c.
Horsley's Apparatus—Table of Firing points—The Government Heat-Test
Apparatus for Dynamites—Nitro-Glycerine, Nitro-Cotton, and Smokeless
Powders—Liquefaction and Exudation Tests—Page's Regulator for Heat-Test
Apparatus—Specific Gravities of Explosives—Table of Temperature of
Detonation, Sensitiveness, &c.
~The Firing Point of Explosives.~—The firing point of an explosive may be determined as follows:—A copper dish, about 3 inches deep, and 6 or more wide, and fitted with a lid, also of copper, is required. The lid contains several small holes, into each of which is soldered a thick copper tube about 5 mm. in diameter, and 3 inches long, with a rather larger one in the centre in which to place a thermometer. The dish is filled with Rose's metal, or paraffin, according to the probable temperature required. The firing point is then taken thus:—After putting a little piece of asbestos felt at the bottom of the centre tube, the thermometer is inserted, and a small quantity of the explosive to be tested is placed in the other holes; the lid is then placed on the dish containing the melted paraffin or metal, in such a way that the copper tubes dip below the surface of the liquid; the temperature of the bath is now raised until the explosive fires, and the temperature noted. The initial temperature should also be noted.
THE FIRING POINT OF VARIOUS EXPLOSIVES (by C. E. Munroe).
(Horsley's Apparatus used.)
_____________________________________________________________________ | | °C. Nitro-glycerine, 5 years old (a single drop taken) | 203-205 Gun-cotton (compressed military cotton, sp. gr. 1.5) | 192-201 Air-dried gun-cotton, stored for 4 years | 179-187 Ditto, stored for 1 year | 187-189 Air-dried collodion-cotton, long staple "Red Island | cotton," 3 years old | 186-191 Air-dried collodion, 3 years old, stored wet | 197-199 Hydro-nitro-cellulose | 201-213 Kieselguhr dynamite, No. 1 | 197-200 Explosive gelatine | 203-209 Mercury fulminate | 175-181 Gunpowder (shell) | 278-287 Hill's picric powder (shells) Been in store 10 years. | 273-283 Ditto (musket) Composed of— | 282-290 Ammonium picrate 42.18 % | Potassium picrate 53.79 " | Charcoal (alder) 3.85 " | ________ | | 99.82 | Forcite, No. 1 | 187-200 Atlas powder (75% NG) | 175-185 Emmensite, No. 1 Sample had been stored in | 167-184 magazine for some months in | a wooden box. | " No. 2 Stored in tin case. | 165-177 " No. 5 " " | 205-217 __________________________________________________________|__________ | | | °C. | Powder used in Chassepôt rifle | 191 | By Leygue & Champion. French gunpowder | 295 | " " Rifle powder (picrate) | 358 | " " Cannon | 380 | " " __________________________________|_________|________________________
Horsley's apparatus consists of an iron stand with a ring support, holding a hemispherical iron vessel or bath in which solid paraffin is put. Above this is another movable support, from which a thermometer is suspended, and so adjusted that its bulb is immersed in the material contained in the iron vessel. A thin copper cartridge-case, 5/8 inch in diameter and 1-15/16 inch long, is suspended over the bath by means of a triangle, so that the end of the case is just 1 inch below the surface of the molten material. On beginning the experiment of determining the firing point of any explosive, the material in the bath is heated to just above the melting point; the thermometer is inserted in it, and a minute quantity of the explosive is placed in the bottom of the cartridge-case. The initial temperature is noted, and then the cartridge-case containing the explosive is inserted in the bath. The temperature is quickly raised until the contents of the cartridge-case flash off or explode, when the temperature is noted as the firing point.
[Illustration: FIG. 46.—HEAT TEST APPARATUS.]
Professor C.E. Munroe, of the U.S. Torpedo Station, has determined the firing point of several explosives by means of this apparatus.