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Pyrotechnic experiments
204
Mechanics,
Physiee,
and Chemistry.
mys an important point, we have not yet sufficient data to form an We, however, have Mr. Mellsnd’s authority for stating that, opmion. taking into account the smaller quantity required to give an equal effect, the cost of the safety gunpeper will be from 30 to 50 per cent. less than that of gunpowder. From what has already been stated, the relative merits of gunpnper and gunpowder will be clearly seen, and a very 'strong prima facie case is ma,d8 out in fuvor of the former. It remains for time and extended application to bring out any latent defects it nmy possibly possess, and which could not he expected to manifest themselves at our limited trial. We trust Mr. Melland’s enterprise in introducing the-safety gunpaper may meet with the success it merits. As far as our knowledge of the new material and its oxpahilities extends, we have no reason to fear that the ultimate results will prove otherwise than satisfactory,
Pyrotechnic From
the London
Experimente. Chemical
New,
No. 387.
On looking over a number of receipts, collected among my earlier days of chemical experimenting, I came upon a number of original receipts for colored stars, for rockets, Roman candles, and shells, which, as they were the result of many experiments, I can confidently recommend as very brilliant in color and good, and I venture to hope that not only amateurs, but even some professional pyrotechnists, may find the receipts serviceable, for even in professional exhibitions some of the colors are often sadly wanting in brilliancy. The ingredients for each of these stars for rocket-heads, &TX.,is powdered separately, and then the whole is made up into a thick paste with water, which is rolled out to the proper thickness and punched into square stars and carefully dried till quite hard. nitrate strontia, 4 ; chlorate potash, 2 ; sul1. Red Rare .-Dried phur, 2; black sulphide antimony, 1. haryta, 5 ; chlorate potash, 2 ; sulphur, 2. Green Star8 .--Nitra.te 2; black SbS,, 1. potash, 49 ; sulphur, 25; chalk, 20 ; 3. Lilac Stars .-Chlorate black CuO, 6. potash, 42; pure nitrate pot4. Purple or Blue Stare. -Chlorate ash, 22; sulphur, 22; CuO, 10. With regard to the remaining receipts, I am not able to state whether they are original or not at this distance of time; still, as they are all well proved, I venture to send them, if they will not take up too mu& room in your journal: 5. White #tars.-Saltpetre, 16 ; sulphur, 4 ; black sulphide anti-
mony, 5. Blasting
powder at 6d. per pound, reduced to powder, is meant in
the following receipts : 6. Tailed Stare .-Blasting coarse charcoal,
8.
powder,
8 ; eulphur,
8;
saltpetre,
8;
Conrumpda’on of Baa for Economic
Purpopoees.
205
Charge,for two-ounce rockets.-Blasting powder, 20 ; charcoal, 6 ; saltpetre, 4. A moderate amount of blasting powder for the head to light and disguise the stars. Composition for Roman candles between the stars lying on powder at Is. 3d. per pound. -Ssltpetre, 5 ; blast powder, 14 ; aulphur, 1; sand, 1. Spur Fire.-Saltpetre, 44 ; sulphur, 2 ; finely powdered and mixed, and then gently rubbed with lamp-black, 14; pack in cases 6 inches long and 9 inch internal diameter. So far for the receipts. Having had occasion to speak of baryta and strontia, I may as well take this opportunity for mentioning a fact the discovery of which, some years ago, ioterested me much, and may prove interesting to such of your readers as are mineralogists, and know Clifton from its beautiful suspension bridge or otherwise. Geological books state that sulphate of bargta exists in our Clifton rocks. After much trouble in my early days I found it in the form of red veins traversing the limestone cliffs. No other sulphate of baryta, 1 believe, was known in the neighborhood. Sulphate of strontia, I believe, wa.s not known to bo found nearer than Aust-passage, until a quantity was found at Pylehill railway cutting, Bristol, a few years ago, and I once found some crystals at Clevedon, twelve miles distant, in the sea-cliffs. But during the lest few years a number of field8 running directly eastward8 from the Clifton downs towards Cotham, and familiar from childhood, have been disturbed, the grass has been taken up, and numberThis has disclosed, lying horizontally over the less buildings erected. upturned limestone strata forming the Clifton rocks and downs, a layer of uew red sandstone of pale-yellow color. This layer abounds in masses of white pulverulent sulphate of baryta and fine crystals of sulphate of Citron&. E. A. H.
On the Comtustion of Gas for Economic Purposes. By Dr. LETHEBY. (A Lecture delivered before the British Association of Gas Yanagera.) From the London
Chemical
Rows, No. 341.
close of the last lecture which I had the honor of delivering to this Association at tbe meeting in Birmingham, I referred very briefly to the general phenomena of gaseous combustion, and to the principles of the economic US! of coal-gas. It was my intention, indeed, to have entered fully into thl8 matter ; but 80 much time was occupied in the examination of the chemical and physical properties of the moat important constituents of Coal -gas, that little was left for the considera1 have, therefore, been requested to tioh of this part of our subject. make it the especial subject-matter of this evening’8 letture; and, in or&r that you may follow me through the various detail8 of the inquiry, it will be necessary to pursye It from the beginning. Ilie phenomena of vlslble combustion are always the re.gults of ener18 VOL.JJI.__THIRD SIERILB.-~O. 3.-8EPTEbiBPR, 1866. At
the
Mechanics,
Physiee,
and Chemistry.
mys an important point, we have not yet sufficient data to form an We, however, have Mr. Mellsnd’s authority for stating that, opmion. taking into account the smaller quantity required to give an equal effect, the cost of the safety gunpeper will be from 30 to 50 per cent. less than that of gunpowder. From what has already been stated, the relative merits of gunpnper and gunpowder will be clearly seen, and a very 'strong prima facie case is ma,d8 out in fuvor of the former. It remains for time and extended application to bring out any latent defects it nmy possibly possess, and which could not he expected to manifest themselves at our limited trial. We trust Mr. Melland’s enterprise in introducing the-safety gunpaper may meet with the success it merits. As far as our knowledge of the new material and its oxpahilities extends, we have no reason to fear that the ultimate results will prove otherwise than satisfactory,
Pyrotechnic From
the London
Experimente. Chemical
New,
No. 387.
On looking over a number of receipts, collected among my earlier days of chemical experimenting, I came upon a number of original receipts for colored stars, for rockets, Roman candles, and shells, which, as they were the result of many experiments, I can confidently recommend as very brilliant in color and good, and I venture to hope that not only amateurs, but even some professional pyrotechnists, may find the receipts serviceable, for even in professional exhibitions some of the colors are often sadly wanting in brilliancy. The ingredients for each of these stars for rocket-heads, &TX.,is powdered separately, and then the whole is made up into a thick paste with water, which is rolled out to the proper thickness and punched into square stars and carefully dried till quite hard. nitrate strontia, 4 ; chlorate potash, 2 ; sul1. Red Rare .-Dried phur, 2; black sulphide antimony, 1. haryta, 5 ; chlorate potash, 2 ; sulphur, 2. Green Star8 .--Nitra.te 2; black SbS,, 1. potash, 49 ; sulphur, 25; chalk, 20 ; 3. Lilac Stars .-Chlorate black CuO, 6. potash, 42; pure nitrate pot4. Purple or Blue Stare. -Chlorate ash, 22; sulphur, 22; CuO, 10. With regard to the remaining receipts, I am not able to state whether they are original or not at this distance of time; still, as they are all well proved, I venture to send them, if they will not take up too mu& room in your journal: 5. White #tars.-Saltpetre, 16 ; sulphur, 4 ; black sulphide anti-
mony, 5. Blasting
powder at 6d. per pound, reduced to powder, is meant in
the following receipts : 6. Tailed Stare .-Blasting coarse charcoal,
8.
powder,
8 ; eulphur,
8;
saltpetre,
8;
Conrumpda’on of Baa for Economic
Purpopoees.
205
Charge,for two-ounce rockets.-Blasting powder, 20 ; charcoal, 6 ; saltpetre, 4. A moderate amount of blasting powder for the head to light and disguise the stars. Composition for Roman candles between the stars lying on powder at Is. 3d. per pound. -Ssltpetre, 5 ; blast powder, 14 ; aulphur, 1; sand, 1. Spur Fire.-Saltpetre, 44 ; sulphur, 2 ; finely powdered and mixed, and then gently rubbed with lamp-black, 14; pack in cases 6 inches long and 9 inch internal diameter. So far for the receipts. Having had occasion to speak of baryta and strontia, I may as well take this opportunity for mentioning a fact the discovery of which, some years ago, ioterested me much, and may prove interesting to such of your readers as are mineralogists, and know Clifton from its beautiful suspension bridge or otherwise. Geological books state that sulphate of bargta exists in our Clifton rocks. After much trouble in my early days I found it in the form of red veins traversing the limestone cliffs. No other sulphate of baryta, 1 believe, was known in the neighborhood. Sulphate of strontia, I believe, wa.s not known to bo found nearer than Aust-passage, until a quantity was found at Pylehill railway cutting, Bristol, a few years ago, and I once found some crystals at Clevedon, twelve miles distant, in the sea-cliffs. But during the lest few years a number of field8 running directly eastward8 from the Clifton downs towards Cotham, and familiar from childhood, have been disturbed, the grass has been taken up, and numberThis has disclosed, lying horizontally over the less buildings erected. upturned limestone strata forming the Clifton rocks and downs, a layer of uew red sandstone of pale-yellow color. This layer abounds in masses of white pulverulent sulphate of baryta and fine crystals of sulphate of Citron&. E. A. H.
On the Comtustion of Gas for Economic Purposes. By Dr. LETHEBY. (A Lecture delivered before the British Association of Gas Yanagera.) From the London
Chemical
Rows, No. 341.
close of the last lecture which I had the honor of delivering to this Association at tbe meeting in Birmingham, I referred very briefly to the general phenomena of gaseous combustion, and to the principles of the economic US! of coal-gas. It was my intention, indeed, to have entered fully into thl8 matter ; but 80 much time was occupied in the examination of the chemical and physical properties of the moat important constituents of Coal -gas, that little was left for the considera1 have, therefore, been requested to tioh of this part of our subject. make it the especial subject-matter of this evening’8 letture; and, in or&r that you may follow me through the various detail8 of the inquiry, it will be necessary to pursye It from the beginning. Ilie phenomena of vlslble combustion are always the re.gults of ener18 VOL.JJI.__THIRD SIERILB.-~O. 3.-8EPTEbiBPR, 1866. At
the