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Explosion of an electric transformer
718
CURRENT TOPICS.
[J. F. I.
The Gyro-compass in the Navy. ANON. (Sci. Amer., cxii, No. 7, I53.)--Gyro-compasses have now been installed on twenty battleships, one armored cruiser, and fifteen submarines of the United States Navy, and it has recently been decided to install master compasses in duplicate on all battleships of the Delaware class and later. Special attention is being paid to the instructions of officers and men in the care and use of these compasses by sending them for a month's instruction at the New York Navy Yard or at the works where the compasses are made. The Bureau of Navigation also maintains with the Atlantic fleet two chief gunners who h a v e been specially trained as gyro-compass experts, their duty being to inspect and adjust the compasses and give instrnction in their use. India R u b b e r P r o d u c t i o n in igI 4. S. tqG~IS AND CO. (India Rubber J., xlix, 77.)--In I9r4, 14,8oo tons of plantation rubber were exported from Ceylon and India and 49,7o0 tons from Malaya, etc., as compared with II,8'3o tons and 36,2o0 tons respectively in i913; the I914 figures, do not include some direct Dutch shipments. The supply from Brazil, including Amazonas, Polivia. Peru, etc., was 37,0oo tons in I9I 4, against 39,0oo tons in t9i 3. The total production of raw rubber in I9~4 is estimated at I ~5,5oo tons. Practically no guayule was made and less reclaimed rubber was used. Exports in I914 from West Africa amounted to 85oo tons, from Loanda 45o tons, and from Congo, French Congo, and Sudan 39oo tons, the corresponding figures for I9I 3 being m,oo0, 4oo, and 44oo tons respectively. England imported 265 o tons and France I7OO tons from West Africa in I9I 4. E x p l o s i o n of an Electric T r a n s f o r m e r . Az~ON. (Sci. Amer. Supple., lxxix, No. 2o4o, 8 9 . ) - - T h e explosion of a large e l e c t r i c transformer in South Africa appears to have developed a new fact that was not known before. In taking down the transformer for repairs the workmen proceeded to drain the expansion tank located above the transformer of the oil it contained, and before doing so a man held a lighted match over a slight hole in the tank, when a severe explosion occurred that either killed or severely burned every man present, besides setting fire to everything inflammable in the transformer chamber. As the oil in the tank was not above 34 ° C., and its flash-point was I4o ° C., the gas that caused the explosion could not have been oil-vapor, and experiments were instituted, using extra high tension discharges under transformer oil. Samples of the resulting gases were collected, which oi1 analysis proved to contain at least 62 per cent. hydrogen. It is evident, from this experience, that great care should be exercised not to allow a naked light near transformer oil tanks or oil switches until they haye been' thoroughly ventilated.
CURRENT TOPICS.
[J. F. I.
The Gyro-compass in the Navy. ANON. (Sci. Amer., cxii, No. 7, I53.)--Gyro-compasses have now been installed on twenty battleships, one armored cruiser, and fifteen submarines of the United States Navy, and it has recently been decided to install master compasses in duplicate on all battleships of the Delaware class and later. Special attention is being paid to the instructions of officers and men in the care and use of these compasses by sending them for a month's instruction at the New York Navy Yard or at the works where the compasses are made. The Bureau of Navigation also maintains with the Atlantic fleet two chief gunners who h a v e been specially trained as gyro-compass experts, their duty being to inspect and adjust the compasses and give instrnction in their use. India R u b b e r P r o d u c t i o n in igI 4. S. tqG~IS AND CO. (India Rubber J., xlix, 77.)--In I9r4, 14,8oo tons of plantation rubber were exported from Ceylon and India and 49,7o0 tons from Malaya, etc., as compared with II,8'3o tons and 36,2o0 tons respectively in i913; the I914 figures, do not include some direct Dutch shipments. The supply from Brazil, including Amazonas, Polivia. Peru, etc., was 37,0oo tons in I9I 4, against 39,0oo tons in t9i 3. The total production of raw rubber in I9~4 is estimated at I ~5,5oo tons. Practically no guayule was made and less reclaimed rubber was used. Exports in I914 from West Africa amounted to 85oo tons, from Loanda 45o tons, and from Congo, French Congo, and Sudan 39oo tons, the corresponding figures for I9I 3 being m,oo0, 4oo, and 44oo tons respectively. England imported 265 o tons and France I7OO tons from West Africa in I9I 4. E x p l o s i o n of an Electric T r a n s f o r m e r . Az~ON. (Sci. Amer. Supple., lxxix, No. 2o4o, 8 9 . ) - - T h e explosion of a large e l e c t r i c transformer in South Africa appears to have developed a new fact that was not known before. In taking down the transformer for repairs the workmen proceeded to drain the expansion tank located above the transformer of the oil it contained, and before doing so a man held a lighted match over a slight hole in the tank, when a severe explosion occurred that either killed or severely burned every man present, besides setting fire to everything inflammable in the transformer chamber. As the oil in the tank was not above 34 ° C., and its flash-point was I4o ° C., the gas that caused the explosion could not have been oil-vapor, and experiments were instituted, using extra high tension discharges under transformer oil. Samples of the resulting gases were collected, which oi1 analysis proved to contain at least 62 per cent. hydrogen. It is evident, from this experience, that great care should be exercised not to allow a naked light near transformer oil tanks or oil switches until they haye been' thoroughly ventilated.