A Dictionary of Arts, Manufactures and Mines

Chapter II: Application of Light-Gas (2)

Text size

+--------------+------------------------------+------------------+--------+
|Name of the |Price of Gas per Meter, and |Price of Coal, and|Average |
|Place where |Discounts allowed. |Description; de- |Quantity|
|Gas Works | |livered per Ton. |of Gas |
|are situated. | | |made per|
| | | |Ton of |
| | | |Coals. |
+--------------+------------------------------+------------------+--------+
| | | |_Cu. |
| | | |ft._ |
+--------------+------------------------------+------------------+--------+
|Birmingham Gas|10_s._ per meter cub. feet. |Lump coal from |6,500 |
|Company. | Discounts |West Bromwich pits| |
| | per an. per cent. |risen much of | |
| | 10_l._ to 30_l._ 2-1/2 |late. 1837, 11_s._| |
| | 30_l._ to 50_l._ 5 |10_d._ | |
| | 50_l._ to 75_l._ 7-1/2 | | |
| | 75_l._ to 100_l._ 10 | | |
| |100_l._ & upwards 15 | | |
+--------------+------------------------------+------------------+--------+
|Birmingham and|10_s._ per meter cub. feet. |From West Bromwich|6,500 |
|Staffordshire.|Discounts as above. |pits, 1837, 9_s._ | |
| | |3_d._ | |
+--------------+------------------------------+------------------+--------+
|Macclesfield. |10_s._ per meter cub. feet. |Common, 8_s._ |6,720 |
| | Discounts |average 1831 | |
| |Above and not per cent. | | |
| | exceeding | | |
| | 50_l._ 75_l._ 5 | | |
| | 75_l._ 100_l._ 7-1/2 | | |
| |100_l._ 125_l._ 10 | | |
| |125_l._ 150_l._ 12-1/2 | | |
| |150_l._ 175_l._ 15 | | |
| |175_l._ 200_l._ 17-1/2 | | |
| |200_l._ & upwards 20. | | |
+--------------+------------------------------+------------------+--------+
|Stockport. |10_s._ per meter cub. feet. |Coal 10_s._ 6_d._ |7,800 |
| |Discounts same as Maccles- |cannel 19_s._ | |
| |field. Macclesfield discounts |6_d._ about half | |
| |taken from Stockport card. |and half used. | |
| | |Average 15_s._ | |
| | |1834. | |
+--------------+------------------------------+------------------+--------+
|Manchester. |10_s._ per m. cub. ft. 1834. |15_s._ 2_d._ |9,500 |
| | 9_s._ and 8_s._ -- 1837. |average. | |
| | Discounts |Oldham } | |
| | and under per cent.|Watergate }cannel.| |
| | 50_l._ 100_l._ 2-1/2 |Wigan } | |
| |100_l._ 150_l._ 5 |Mixed, 1834. | |
| |150_l._ 200_l._ 7-1/2 | | |
| |200_l._ 225_l._ 10 | | |
| |225_l._ 250_l._ 12-1/2 | | |
| |250_l._ 300_l._ 15 | | |
| |300_l._ 400_l._ 17-1/2 | | |
| |400_l._ and upwards 20 | | |
+--------------+------------------------------+------------------+--------+
|Liverpool Old |10_s._ per meter cub. feet. |7_s._ 3_d._ per |8,200 |
|Company, 1834.| Discounts per ct.|ton of 112 lbs. | |
| | 10_l._ & under 50_l._ 2-1/2|per cwt. Ormskirk | |
| | 50_l._ to 100_l._ 5 |or Wigan slack. | |
| |100_l._ to 200_l._ 7-1/2| | |
| |300_l._ & upwards 10 | | |
+--------------+------------------------------+------------------+--------+
|Ditto ditto. |In 1835 this Company resorted to the use of cannel coal |
| |similar to the Liverpool New Gas and Coal Company, pro- |
| |ducing nearly similar results, which see. |
+--------------+------------------------------+------------------+--------+
|Liverpool New |10_s._ per meter cub. feet. |18_s._ all cannel |9,500 |
|Gas and Coke, |Discounts same as Liverpool |Wigan. | |
|1835. |Old Company. | | |
+--------------+------------------------------+------------------+--------+
|Bradford, |9_s._ per meter cubic feet to |8_s._ 6_d._ per |8,000 |
|1834. |large consumers. |ton. 3 sorts used | |
| | Discounts per cent. |average. Slack | |
| | 20_l._ to 30_l._ 5 |5_s._ 6_d._ Low | |
| | 30_l._ to 40_l._ 7-1/2 |moor 8_s._ 10_d._ | |
| | 40_l._ to 60_l._ 10 |Catherine slack | |
| | 60_l._ to 80_l._ 12-1/2 |8_s._ | |
| | 80_l._ to 100_l._ 15 | | |
| |100_l._ & upwards 20 | | |
| |Small consumers, 10_s._ per | | |
| |meter cub. feet, and 5 per | | |
| |cent. off from 10_l._ to | | |
| |20_l._ | | |
+--------------+------------------------------+------------------+--------+
|Leeds, 1834. |8_s._ per meter cubic feet. |8_s._ per ton av- |6,500 |
| | Discounts |erage. 2-3ds com- | |
| | 2-1/2}per cent.{ 15_l._ |mon 7_s._ 1-3d | |
| | 5 }on half- { 30_l._ |cannel, 10_s._ | |
| | 7-1/2}yearly { 50_l._ | | |
| |10 }payments { 100_l._ | | |
+--------------+------------------------------+------------------+--------+
|Sheffield, |8_s._ per meter cubic feet. |7_s._ 9_d._ per |8,000 |
|1835. |Discounts same as Leeds. |ton average. 3 | |
| | |sorts used 1, | |
| | |2-10ths. cannel, | |
| | |at 16_s._ 8, | |
| | |2-10ths. deep pit,| |
| | |7_s._ 1-10th silk | |
| | |stone, 10_s._ | |
+--------------+------------------------------+------------------+--------+
|Leicester, |7_s._ 6_d._ per meter cub. ft.|13_s._ 6_d._ aver-|7,500 |
|1837. |Discounts on half-yearly |age. Derbyshire | |
| |rental not exceeding 10_l._, |soft coal. | |
| |5 per cent. | | |
| |Above and not per cent. | | |
| | exceeding | | |
| |10_l._ 20_l._ 7-1/2 | | |
| |20_l._ 30_l._ 10 | | |
| |30_l._ 40_l._ 12-1/2 | | |
| |40_l._ 50_l._ 15 | | |
| |50_l._ 60_l._ 20 | | |
| |60_l._ & upwards 25 | | |
+--------------+------------------------------+------------------+--------+
|Derby, 1834. |10_s._ per meter cub. feet. |Same coal used as |7,000 |
| |Discounts 5 to 35 per cent. |at Leicester. | |
+--------------+------------------------------+------------------+--------+
|Nottingham, |9_s._ per meter cubic feet. |Ditto. |7,000 |
|1834. |Discounts as above. | | |
+--------------+------------------------------+------------------+--------+
|London, 1834. |10_s._ per meter cub. feet. No|17_s._ average. |8,500 |
| |discounts. |Newcastle. | |
+--------------+------------------------------+------------------+--------+
|Ditto, 1837. |Ditto. |Ditto. |8,500 |
+--------------+------------------------------+------------------+--------+

+--------------+-----------+-------------+---------+--------+-------------+
|Name of the |Coke made |Selling Price|Material |Quantity|No. of Public|
|Place where |from a Ton |of Coke. |used to |used per|or Street |
|Gas Works |of Coal. | |heat Re- |Ton of |Lamps |
|are situated. | | |torts. |Coal. |supplied. |
+--------------+-----------+-------------+---------+--------+-------------+
|Birmingham Gas|32 bushels.|2_s._ 1_d._ |Slack. |About 5 | 490 |
|Company. | |per quarter | |cwt. of | |
| | |delivered, or| |slack, | |
| | |about 3_d._ | |at 6_s._| |
| | |per bushel. | |per ton,| |
| | | | |25 per | |
| | | | |cent. | |
+--------------+-----------+-------------+---------+--------+-------------+
|Birmingham and|24 bush. |2_s._ 10_d._ |Slack and|5 cwt. |1,500 |
|Staffordshire.|but larger |per sack of 8|Tar. |of | |
| |measure |bushels. | |slack, | |
| |than Bir- | | |at 4_s._| |
| |mingham. | | |25 per | |
| | | | |cent. | |
+--------------+-----------+-------------+---------+--------+-------------+
|Macclesfield. |12 cwt. |10_s._ per |Coke. |No ac- | 220 |
| | |ton. | |count | |
| | | | |kept. | |
+--------------+-----------+-------------+---------+--------+-------------+
|Stockport. |7 cwt. |6_s._ 8_d._ |Coal, |Ditto. | 230 |
| | |per ton. |coke, and| | |
| | | |tar. | | |
+--------------+-----------+-------------+---------+--------+-------------+
|Manchester. |14 cwt. |Ditto. |Coke. |4, 2-3ds|2,375 |
| | | | |cwt. | |
+--------------+-----------+-------------+---------+--------+-------------+
|Liverpool Old |11-3/4 cwt.|8_s._ 4_d._ |Slack |6-1/2 |1,700 30 |
|Company, 1834.| |per ton of |7_s._ |cwt. | |
| | |112 lb. per |3_d._ | | |
| | |cwt. |per ton. | | |
+--------------+-----------+-------------+---------+--------+-------------+
|Ditto ditto. |In 1835 this Company resorted to the use of cannel coal |
| |similar to the Liverpool New Gas and Coal Company, pro- |
| |ducing nearly similar results, which see. |
+--------------+-----------+-------------+---------+--------+-------------+
|Liverpool New |13 cwt. |7_s._ 6_d._ |Coke and |5-1/2 |Only a few. |
|Gas and Coke, | |per ton. |slack. |cwt. | |
|1835. | | | | | |
+--------------+-----------+-------------+---------+--------+-------------+
|Bradford, |13 cwt. |12_s._ per |Coke. |8-1/2 |220 |
|1834. | |ton. | |cwt. | |
+--------------+-----------+-------------+---------+--------+-------------+
|Leeds, 1834. |12 cwt. |7_s._ 6_d._ |Ditto. |5-1/4 |517 |
| | |per ton. | |cwt. | |
+--------------+-----------+-------------+---------+--------+-------------+
|Sheffield, |10 cwt. of |10_s._ per |Ditto. |3-1/2 |600 |
|1835. |saleable |ton. | |cwt. | |
| |coke. | | | | |
+--------------+-----------+-------------+---------+--------+-------------+
|Leicester, |4 quarters.|10_s._ 8_d._ |Coke |About |414 |
|1837. | |or 2_s._ |tar, &c. |1-3d of | |
| | |8_d._ per qr.| |coke. | |
+--------------+-----------+-------------+---------+--------+-------------+
|Derby, 1834. |Ditto. |Ditto. |Coke. |Ditto. |219 |
+--------------+-----------+-------------+---------+--------+-------------+
|Nottingham, |Ditto. |Ditto. |Ditto. |Ditto. |300 |
|1834. | | | | | |
+--------------+-----------+-------------+---------+--------+-------------+
|London, 1834. |36 bush. |12_s._ per |Ditto. |13 bush.|26,280 |
+--------------+-----------+-------------+---------+--------+-------------+
|Ditto, 1837. |Ditto. |Ditto. |Ditto. |Ditto. |30,400 |
+--------------+-----------+-------------+---------+--------+-------------+

+--------------+------------+---------+----------+------------------------+
|Name of the |Gas consumed|Rate per |Amount de-|Per Centage of Loss of |
|Place where |in each Lamp|Meter Cu-|ducted for|Gas made. |
|Gas Works |per Hour. |bic Feet |cleaning, | |
|are situated. | |received |lighting, | |
| | |for |extin- | |
| | |Ditto. |guishing, | |
| | | |providing | |
| | | |Lamp | |
| | | |Posts; &c.| |
+--------------+------------+---------+----------+------------------------+
| | |_s. d._ |_s. d._ | |
+--------------+------------+---------+----------+------------------------+
|Birmingham Gas|5 feet per |30 10 |18 0 |Receives net about 6_s._|
|Company. |hour. |40 18 | |8_d._ per meter cubic |
| | | | |feet. |
+--------------+------------+---------+----------+------------------------+
|Birmingham and|Ditto. | 1 3-1/2|18 0 |Receives net about 5_s._|
|Staffordshire.| | | |6_d._ per meter cubic |
| | | | |feet. |
+--------------+------------+---------+----------+------------------------+
|Macclesfield. |4 feet per | 3 0 |12 0 |Could not say. |
| |hour. | | | |
+--------------+------------+---------+----------+------------------------+
|Stockport. |Ditto. | 2 6 |12 6 |Ditto. |
+--------------+------------+---------+----------+------------------------+
|Manchester. |1 foot, | 6 6 |nothing. |About 15 to 17-1/2 per |
| |2 feet, per | 5 6 | |cent. receive about |
| |hour. | | |7_s._ 4_d._ per meter |
| | | | |cubic feet, public and |
| | | | |private. Nearly all by |
| | | | |meter. |
+--------------+------------+---------+----------+------------------------+
|Liverpool Old |5 feet per | 4 4 |12 0 |Could not learn in the |
|Company, 1834.|hour. | | |absence of the manager. |
+--------------+------------+---------+----------+------------------------+
|Ditto ditto. |In 1835 this Company resorted to the use of cannel coal |
| |similar to the Liverpool New Gas and Coal Company, pro- |
| |ducing nearly similar results, which see. |
+--------------+------------+---------+----------+------------------------+
|Liverpool New |3-1/2 feet | 5 6 |nothing. |Nearly all by meter. |
|Gas and Coke, |per hour. | | | |
|1835. | | | | |
+--------------+------------+---------+----------+------------------------+
|Bradford, |5 feet per | 3 1 |12 6 |Receive 8_s._ per meter |
|1834. |hour. | | |cubic feet, less 5-1/2 |
| | | | |per cent. |
+--------------+------------+---------+----------+------------------------+
|Leeds, 1834. |4 feet per | 5 2 | 3 10 |Receive for public and |
| |hour. | | |private 6_s._ 8_d._ per |
| | | | |meter cubic feet. Public|
| | | | |5_s._, private 7_s._; |
| | | | |meters used to 5 to 1 |
| | | | |for private rental. |
+--------------+------------+---------+----------+------------------------+
|Sheffield, |Ditto. | 3 2-1/2|18 0 |Receive for public and |
|1835. | | | |private lts. 5_s._ per |
| | | | |meter cubic feet. Public|
| | | | |3_s._ 2-1/2_d._, private|
| | | | |5_s._ 9-1/2_d._ Few |
| | | | |meters used. |
+--------------+------------+---------+----------+------------------------+
|Leicester, |5 feet per | 3 4-3/4| 7 0 |Not sufficiently long, |
|1837. |hour. | | |at 7_s._ 6_d._ |
+--------------+------------+---------+----------+------------------------+
|Derby, 1834. |Ditto. | 4 0 | ---- |Lose about 17-1/2 per |
| | |nearly. | |cent. |
+--------------+------------+---------+----------+------------------------+
|Nottingham, |Ditto. | 3 0 | ---- |Could not learn. |
|1834. | |nearly. | | |
+--------------+------------+---------+----------+------------------------+
|London, 1834. |4 feet per | 4 0 |12 0 |Receive for public and |
| |hour. | | |private lights 7_s._ |
| | | | |public, 4_s._ private, |
| | | | |8_s._ few meters used. |
+--------------+------------+---------+----------+------------------------+
|Ditto, 1837. |Ditto. | 4 0 |12 0 |Ditto. |
+--------------+------------+---------+----------+------------------------+

+--------------+--------------+--------+---------+---------+--------+
|Name of the |Greatest Quan-|Duration|Method of|Number of|Specific|
|Place where |tity of Gas |of Char-|Purifica-|Gas |Gravity |
|Gas Works |delivered in |ges. |tion. |Holders. |of the |
|are situated. |One Night. | | | |Gas. |
| | | | | | |
| | | | | | |
| | | | | | |
| | | | | | |
| | | | | | |
+--------------+--------------+--------+---------+---------+--------+
| |_Cubic Feet._ | | | | |
+--------------+--------------+--------+----------+--------+--------+
|Birmingham Gas|48 millions in|6 hours.|Dry lime.|4, and 2 |·453 |
|Company. |the year. | | |in the | |
| | | | |town, and| |
| | | | |large new| |
| | | | |gas | |
| | | | |station. | |
+--------------+--------------+--------+---------+---------+--------+
|Birmingham and|85 millions in|Ditto. |Ditto. |6, and 6 |·455 |
|Staffordshire.|the year. | | |in the | |
| | | | |town 7 | |
| | | | |miles | |
| | | | |off. | |
+--------------+--------------+--------+---------+---------+--------+
|Macclesfield. |80,000. Total |8 hours.|Ditto. |3 gas |Not |
| |for year about| | |holders. |taken. |
| |15 millions. | | | | |
+--------------+--------------+--------+---------+---------+--------+
|Stockport. |65,000. Total |Ditto. |Ditto. |4 gas |·539 |
| |for year about| | |holders. | |
| |12 millions. | | | | |
+--------------+--------------+--------+---------+---------+--------+
|Manchester. |500,000. Total|6 hours.|Wet lime.|10 gas |·534 |
| |for year 100 | | |holders, | |
| |millions. | | |and 2 in | |
| | | | |the town.| |
+--------------+--------------+--------+---------+---------+--------+
|Liverpool Old |360,000. Total|8 hours,|Wet and |8 gas |·462 |
|Company, 1834.|for year |large |dry lime,|holders | |
| |72 millions. |retorts |princi- |in all, 4| |
| | |holding |pally |in the | |
| | |6 cwt. |dry. |town, | |
| | |each. | |1000 | |
| | | | |yards | |
| | | | |off the | |
| | | | |works. | |
+--------------+--------------+--------+---------+---------+--------+
|Ditto ditto. |In 1835 this Company resorted to the use of cannel |
| |coal similar to the Liverpool New Gas and Coal Com- |
| |pany, producing nearly similar results, which see. |
+--------------+--------------+--------+---------+---------+--------+
|Liverpool New |Not suffi- |4 hours.|Wet lime.|2 large |·580 |
|Gas and Coke, |ciently long | | |gas | |
|1835. |at work. | | |holders. | |
+--------------+--------------+------------------+---------+--------+
|Bradford, |42,500. Total |8 hours.|Dry lime.|4 gas |·420 |
|1834. |for year | | |holders. | |
| |8,619,000. | | | | |
+--------------+--------------+--------+---------+---------+--------+
|Leeds, 1834. |176,000. Total|6 hours.|Ditto. |5 gas |·530 |
| |for year 31 | | |holders. | |
| |millions. | | | | |
+--------------+--------------+--------+---------+---------+--------+
|Sheffield, |220,000. Total|Ditto. |Ditto. |4 gas |·466 |
|1835. |for year 40 | | |holders, | |
| |millions. | | |and 2 | |
| | | | |more | |
| | | | |erecting.| |
+--------------+--------------+--------+---------+---------+--------+
|Leicester, |Total for year|Ditto. |Ditto. |3 gas |·528 |
|1837. |18 millions. | | |holders, | |
| | | | |and 1 | |
| | | | |erecting.| |
+--------------+--------------+--------+---------+---------+--------+
|Derby, 1834. |Ditto. |Ditto. |Wet lime.|4 gas |·448 |
| | | | |holders. | |
+--------------+--------------+--------+---------+---------+--------+
|Nottingham, |Ditto. |Ditto. |Ditto. | ---- |·424 |
|1834. | | | | | |
+--------------+--------------+--------+---------+---------+--------+
|London, 1834. |Total for year|Ditto. |Ditto. |130 gas |·412 |
| |1000 millions.| | |holders. | |
| |Longest night | | | | |
| |4,910,000. | | | | |
+--------------+--------------+--------+---------+---------+--------+
|Ditto, 1837. |Total for year|Ditto. |Ditto. |176 gas |·412 |
| |1460 millions.| | |holders. | |
| |Longest night | | | | |
| |7,120,000. | | | | |
+--------------+--------------+--------+---------+---------+--------+

+--------------+---------+-----------+--------+-------+-------------+
|Name of the |Distance |Gas equal |Gas |Gas |Height of Gas|
|Place where |of Candle|to Candles.|consumed|Flame |Flame equal |
|Gas Works |from |Gas burnt |per Hour|reduced|to Light |
|are situated. |Shadow. |in a single|with a |to Can-|from Candle. |
| | |Jet Four |Four- |dle | |
| | |Inches |Inch |burnt | |
| | |high. |Flame. |per | |
| | | | |Hour. | |
+--------------+---------+-----------+--------+-------+-------------+
| |_Inch._ |_Candles_ |_Cu. |_Cu. |_Inch._ |
| | | |ft._ |ft._ | |
+--------------+---------+-----------+--------+-------+-------------+
|Birmingham Gas|72 |1,929 |1·22 | ·8 |2-1/2 |
|Company. | | | | | |
+--------------+---------+-----------+--------+-------+-------------+
|Birmingham and|72 |1,929 |1·22 | ·8 |2-1/2 |
|Staffordshire.| | | | | |
+--------------+---------+-----------+--------+-------+-------------+
|Macclesfield. |70 | 204 |Not | ·8 |2-3/4 |
| | | |taken. | | |
+--------------+---------+-----------+--------+-------+-------------+
|Stockport. |64 |2,441 | ·85 | ·55 |2-5/8 |
+--------------+---------+-----------+--------+-------+-------------+
|Manchester. |66 |2,295 | ·825 | ·475 |2-1/4 |
+--------------+---------+-----------+--------+-------+-------------+
|Liverpool Old |75 |1,777 |1·1 | ·75 |2-5/8 |
|Company, 1834.| | | | | |
+--------------+---------+-----------+--------+-------+-------------+
|Ditto ditto. |In 1835 this Company resorted to the use of cannel |
| |coal similar to the Liverpool New Gas and Coal Com- |
| |pany, producing nearly similar results, which see. |
+--------------+---------+-----------+--------+-------+-------------+
|Liverpool New |55 |3,306 | ·9 | ·45 |2 |
|Gas and Coke, | | | | | |
|1835. | | | | | |
+--------------+---------+-----------+--------+-------+-------------+
|Bradford, |78 |1,643 | ·12 | ·9 |3 |
|1834. | | | | | |
+--------------+---------+-----------+--------+-------+-------------+
|Leeds, 1834. |67 |2,228 | ·855 | ·51 |2-1/4 |
+--------------+---------+-----------+--------+-------+-------------+
|Sheffield, |74 |1,826 |1·04 | ·735 |2-3/4 |
|1835. | | | | | |
+--------------+---------+-----------+--------+-------+-------------+
|Leicester, |74 |1,826 |1·1 | ·75 |2-3/4 |
|1837. | | | | | |
+--------------+---------+-----------+--------+-------+-------------+
|Derby, 1834. |83 |1,453 |1·2 | ·925 |3 |
+--------------+---------+-----------+--------+-------+-------------+
|Nottingham, |90 |1,234 |1·3 |1·175 |3 |
|1834. | | | | | |
+--------------+---------+-----------+--------+-------+-------------+
|London, 1834. |80 |1,562 |1·13 | ·84 |2-3/4 |
+--------------+---------+-----------+--------+-------+-------------+
|Ditto, 1837. |80 |1,562 |1·13 | ·84 |2-3/4 |
+--------------+---------+-----------+--------+-------+-------------+

A TABLE shewing the Rate per Thousand Cubic feet received for any Burner consuming from 1/2 a Cubic foot to 10 Cubic feet per hour, at any given price per annum, and to the times below stated. By Joseph Hedley, Esq.

+----------------------+------+-----------------+-----------------+
| | | Single Jets. | 2 Jets. |
| | | | |
| | No. +-----+-----+-----+-----+-----+-----+
| Time of Burning | of | Cub.| Cub.| Cub.|Cub. |Cub. |Cub. |
| per annum. |Hours.| ft. | ft. | ft. | ft. | ft. | ft. |
| |[30] | 1/2 | 3/4 | 1 |1-1/4|1-1/2|1-3/4|
+----------------------+------+-----+-----+-----+-----+-----+-----+
|From Dusk to 8 o’clock| 781 |2·56 |1·706|1·28 |1·026|·853 |·731 |
| ditto and Sundays| 902 |2·216|1·478|1·108| ·887|·739 |·633 |
| ditto and from 6 | | | | | | | |
| o’clock mornings | 1050 |1·904|1·27 | ·952| ·762|·635 |·544 |
| ditto and Sundays| | | | | | | |
| and from ditto | 1172 |1·706|1·138| ·853| ·682|·569 |·487 |
| 9 o’clock | 1054 |1·896|1·264| ·948| ·759|·632 |·542 |
| ditto and Sundays| 1221 |1·638|1·092| ·819| ·675|·546 |·463 |
| ditto and from 6 | | | | | | | |
| o’clock mornings | 1323 |1·510|1·066| ·755| ·604|·503 |·431 |
| ditto and Sundays| | | | | | | |
| and from ditto | 1490 |1·342| ·894| ·671| ·536|·447 |·383 |
| 10 o’clock | 1367 |1·462| ·974| ·731| ·585|·487 |·418 |
| ditto and Sundays| 1586 |1·26 | ·84 | ·63 | ·504|·42 |·36 |
| ditto and from 6 | | | | | | | |
| o’clock mornings | 1636 |1·222| ·814| ·611| ·489|·407 |·349 |
| ditto and Sundays| | | | | | | |
| and from ditto | 1855 |1·078| ·718| ·539| ·431|·359 |·308 |
| 11 o’clock | 1680 |1·19 | ·794| ·595| ·476|·397 |·34 |
| ditto and Sundays| 1951 |1·024| ·682| ·512| ·409|·341 |·293 |
| ditto and from 6 | | | | | | | |
| o’clock mornings | 1949 |1·026| ·684| ·513| ·41 |·342 |·294 |
| ditto and Sundays| | | | | | | |
| and from ditto | 2220 | ·9 | ·6 | ·45 | ·36 |·3 |·257 |
| 12 o’clock | 1993 |1· | ·668| ·502| ·4 |·334 |·287 |
| ditto and Sundays| 2316 | ·862| ·574| ·432| ·345|·287 |·247 |
| ditto and from 6 | | | | | | | |
| o’clock mornings | 2262 | ·884| ·59 | ·442| ·353|·295 |·255 |
| ditto and Sundays| | | | | | | |
| and from ditto | 2585 | ·772| ·514| ·387| ·309|·257 |·221 |
| 1 o’clock | 2306 | ·866| ·578| ·434| ·347|·289 |·247 |
| ditto and Sundays| 2681 | ·746| ·498| ·373| ·298|·249 |·213 |
| ditto and from 6 | | | | | | | |
| o’clock mornings | 2575 | ·776| ·518| ·388| ·31 |·259 |·222 |
| ditto and Sundays| | | | | | | |
| and from ditto | 2950 | ·678| ·452| ·339| ·271|·226 |·193 |
| All night | 4327 | ·462| ·308| ·231| ·185|·154 |·132 |
+----------------------+------+-----+-----+-----+-----+-----+-----+

+----------------------+------+----------------+-----------------+
| | | 3 Jets. | Small Argand. |
| | | | |
| | No. +----+-----+-----+-----+-----+-----+
| Time of Burning | of |Cub.|Cub. |Cub. |Cub. |Cub. |Cub. |
| per annum. |Hours.| ft.| ft. | ft. | ft. | ft. | ft. |
| |[30] | 2 |2-1/2| 3 |3-1/2| 4 |4-1/2|
+----------------------+------+----+-----+-----+-----+-----+-----+
|From Dusk to 8 o’clock| 781 |·64 |·5132|·4268|·3658|·3201|·2846|
| ditto and Sundays| 902 |·554|·4434|·3695|·3168|·2771|·2464|
| ditto and from 6 | | | | | | | |
| o’clock mornings | 1050 |·476|·381 |·3174|·272 |·2381|·2116|
| ditto and Sundays| | | | | | | |
| and from ditto | 1172 |·426|·3412|·2844|·2438|·2133|·1896|
| 9 o’clock | 1054 |·474|·3794|·3162|·271 |·2371|·2108|
| ditto and Sundays| 1221 |·409|·3376|·273 |·234 |·2047|·182 |
| ditto and from 6 | | | | | | | |
| o’clock mornings | 1323 |·378|·3022|·2519|·2158|·1889|·1678|
| ditto and Sundays| | | | | | | |
| and from ditto | 1490 |·335|·2684|·2236|·1918|·1675|·1492|
| 10 o’clock | 1367 |·366|·2926|·2438|·209 |·1829|·1626|
| ditto and Sundays| 1586 |·315|·2522|·2101|·1802|·1576|·14 |
| ditto and from 6 | | | | | | | |
| o’clock mornings | 1636 |·305|·2444|·2037|·1746|·1528|·1358|
| ditto and Sundays| | | | | | | |
| and from ditto | 1855 |·269|·2156|·1796|·154 |·1347|·1198|
| 11 o’clock | 1680 |·297|·238 |·1984|·17 |·1488|·133 |
| ditto and Sundays| 1951 |·256|·2048|·1707|·1466|·1281|·1138|
| ditto and from 6 | | | | | | | |
| o’clock mornings | 1949 |·256|·2052|·171 |·1466|·1282|·114 |
| ditto and Sundays| | | | | | | |
| and from ditto | 2220 |·225|·1802|·1501|·1286|·1126|·1 |
| 12 o’clock | 1993 |·251|·2006|·1672|·1434|·1254|·1114|
| ditto and Sundays| 2316 |·215|·1726|·1439|·1236|·1079|·0958|
| ditto and from 6 | | | | | | | |
| o’clock mornings | 2262 |·221|·1768|·1476|·1274|·1105|·0982|
| ditto and Sundays| | | | | | | |
| and from ditto | 2585 |·193|·1546|·1289|·1104|·0967|·0858|
| 1 o’clock | 2306 |·217|·1734|·1445|·1238|·1080|·0962|
| ditto and Sundays| 2681 |·186|·1492|·1243|·1066|·0932|·0828|
| ditto and from 6 | | | | | | | |
| o’clock mornings | 2575 |·194|·1552|·1294|·111 |·0971|·0862|
| ditto and Sundays| | | | | | | |
| and from ditto | 2950 |·169|·1356|·113 |·0968|·0847|·0754|
| All night | 4327 |·115|·6924|·077 |·066 |·0578|·0515|
+----------------------+------+----+-----+-----+-----+-----+-----+

+----------------------+------+-----------------+-----------------+
| | | Large Argand. |Fancy and extra- |
| | | |vagant Burners. |
| | No. +-----+-----+-----+-----+-----+-----+
| Time of Burning | of |Cub. |Cub. |Cub. |Cub. |Cub. |Cub. |
| per annum. |Hours.| ft. | ft. | ft. | ft. | ft. | ft. |
| |[30] | 5 | 6 | 7 | 8 | 9 | 10 |
+----------------------+------+-----+-----+-----+-----+-----+-----+
|From Dusk to 8 o’clock| 781 |·2561|·2134|·1829|·16 |·1423|·128 |
| ditto and Sundays| 902 |·2217|·1848|·1584|·1383|·1232|·1108|
| ditto and from 6 | | | | | | | |
| o’clock mornings | 1050 |·1905|·1587|·136 |·119 |·1058|·0952|
| ditto and Sundays| | | | | | | |
| and from ditto | 1172 |·1706|·1422|·1219|·1067|·0948|·0853|
| 9 o’clock | 1054 |·1897|·1581|·1355|·1185|·1054|·0948|
| ditto and Sundays| 1221 |·1638|·1365|·117 |·1024|·091 |·0819|
| ditto and from 6 | | | | | | | |
| o’clock mornings | 1323 |·1511|·1259|·1079|·0945|·0839|·0755|
| ditto and Sundays| | | | | | | |
| and from ditto | 1490 |·1312|·1118|·0959|·0839|·0746|·0671|
| 10 o’clock | 1367 |·1463|·1219|·1045|·0914|·0813|·0731|
| ditto and Sundays| 1586 |·1261|·1051|·0901|·0789|·07 |·0630|
| ditto and from 6 | | | | | | | |
| o’clock mornings | 1636 |·1222|·1019|·0873|·0764|·0679|·0611|
| ditto and Sundays| | | | | | | |
| and from ditto | 1855 |·1078|·0898|·077 |·0674|·0599|·0539|
| 11 o’clock | 1680 |·119 |·0992|·085 |·0744|·0665|·0595|
| ditto and Sundays| 1951 |·1024|·0854|·0733|·064 |·0569|·0512|
| ditto and from 6 | | | | | | | |
| o’clock mornings | 1949 |·1026|·0855|·0733|·0641|·057 |·0513|
| ditto and Sundays| | | | | | | |
| and from ditto | 2220 |·0981|·0751|·0643|·0563|·05 |·045 |
| 12 o’clock | 1993 |·1003|·0836|·0717|·0627|·0557|·0502|
| ditto and Sundays| 2316 |·0863|·0719|·0618|·0539|·0479|·0432|
| ditto and from 6 | | | | | | | |
| o’clock mornings | 2262 |·0884|·0737|·0637|·0552|·0491|·0442|
| ditto and Sundays| | | | | | | |
| and from ditto | 2585 |·0773|·0645|·0552|·0483|·0429|·0387|
| 1 o’clock | 2306 |·0867|·0723|·0619|·0542|·0481|·0434|
| ditto and Sundays| 2681 |·0746|·0621|·0533|·0466|·0414|·0373|
| ditto and from 6 | | | | | | | |
| o’clock mornings | 2575 |·0776|·0647|·0555|·0485|·0431|·0388|
| ditto and Sundays| | | | | | | |
| and from ditto | 2950 |·0678|·0565|·0484|·0424|·0377|·0339|
| All night | 4327 |·0462|·0385|·033 |·0289|·0257|·0231|
+----------------------+------+-----+-----+-----+-----+-----+-----+

_To use the Table._--Select the hour to which it is agreed the gas is
to burn,--9, 10, 11 o’clock, Sundays, &c., as the case may be, and the
description of the burner.--Multiply the decimal number opposite to it
by the amount in shillings agreed to be paid per annum, and the
product will be the sum received per m. cubic feet for the gas.

_Example._--Suppose a small argand which should burn 3-1/2 feet per
hour, is agreed for till 9 o’clock at 2_l._ per annum. Look along the
line of 9 o’clock till you arrive at the column of 3-1/2 feet per
hour, and you find the number, ·271. Multiply this number by 40_s._
and the result gives 10_s._ 10_d._ per m. cubic feet. But suppose
instead of keeping to 9 o’clock the party burns till 1 o’clock,
Sundays and mornings, and by enlarging the holes or height of flame
consumes 8 cubic feet of gas per hour; then you have the number,
·0424, which multiplied by 40_s._, still the price paid, gives 1_s._
8_d._ per m. cubic feet only, and so on for any greater or lesser
variation of the agreement.

[30] The “number of hours” includes 1/4 of an hour allowed for
shutting shops, and 1 hour’s extra burning on Saturday nights.

GENERAL SUMMARY.

For lighting London and its suburbs with gas, there are--

18 public gas works.

12 do. companies.

2,800,000_l._ capital employed in works, pipes, tanks, gas-holders, apparatus.

450,000_l._ yearly revenue derived.

180,000 tons of coals used in the year for making gas.

1,460,000,000 cubic feet of gas made in the year.

134,300 private burners supplied to about 40,000 consumers.

30,400 public or street do. N. B. about 2650 of these are in the _city_ of London.

380 lamplighters employed.

176 gas-holders; several of them double ones, capable of storing 5,500,000 cubic feet.

890 tons of coals used in the retorts on the shortest day, in 24 hours.

7,120,000 cubic feet of gas used in longest night, say 24th December.

About 2500 persons are employed in the metropolis alone, in this branch of manufacture.

Between 1822 and 1827 the quantity nearly doubled itself, and that in 5 years.

Between 1827 and 1837 it doubled itself again.

Mr. Kirkham, engineer, obtained a patent, in June, 1837, for an improved mode of removing the carbonaceous incrustation from the internal surfaces of gas retorts. He employs a jet or jets of heated atmospheric air, or other gases containing oxygen, which he impels with force into the interior of such retorts as have become incrusted in consequence of the decomposition of the coal. The retort is to be kept thoroughly red hot during the application of the proposed jets. An iron pipe, constructed with several flexible joints, leading from a blowing machine, is bent in such a way as to allow its nozzle end to be introduced within the retort, and directed to any point of its surface.

I should suppose that air, even at common temperatures, applied to a retort ignited to the pitch of making gas, would burn away the incrustations; but hot air will, no doubt, be more powerful.

GAS-HOLDER; a vessel for containing and preserving gas, of which various forms are described by chemical writers.

GASOMETER, means properly a measurer of gas, though it is employed often to denote a recipient of gas of any kind. See the article GAS-LIGHT.

GAUZE WIRE CLOTH; is a textile fabric, either plane or tweelled, made of brass, iron, or copper wire, of very various degrees of fineness and openness of texture. Its chief uses are for sieves, and safety lamps.

GAY-LUSSITE, is a white mineral of a vitreous fracture, which crystallizes in oblique rhomboidal prisms; specific gravity from 1·93 to 1·95; scratches gypsum, but is scratched by calcspar; affords water by calcination; it consists of carbonic acid 28·66; soda, 20·44; lime, 17·70; water, 32·20; clay, 1·00. It is in fact, by my analysis, a hydrated soda-carbonate of lime in atomic proportions. This mineral occurs abundantly in insulated crystals, disseminated through the bed of clay which covers the _urao_, or native sesquicarbonate of soda, at Lagunilla in Colombia.

GELATINE; (Eng. and Fr.; _Gallert_, _Leim_, Germ.) is an animal product which is never found in the humours, but it may be obtained by boiling with water the soft and solid parts; as the muscles, the skin, the cartilages, bones, ligaments, tendons, and membranes. Isinglass consists almost entirely of gelatine. This substance is very soluble in boiling water; the solution forms a tremulous mass of jelly when it cools. Cold water has little action upon gelatine. Alcohol and tannin (tannic acid, see GALL-NUTS) precipitate gelatine from its solution; the former by abstracting the water, the latter by combining with the substance itself into an insoluble compound; of the nature of leather. No other acid, except the tannic, and no alkali possesses the property of precipitating gelatine. But chlorine and certain salts render its solution more or less turbid; as the nitrate and bi-chloride of mercury, the proto-chloride of tin, and a few others. Sulphuric acid converts a solution of gelatine at a boiling heat into sugar. See LIGNEOUS FIBRE. Gelatine consists of carbon, 47·88; hydrogen, 7·91; oxygen, 27·21. See GLUE and ISINGLASS.

GEMS, are precious stones, which, by their colour, limpidity, lustre, brilliant polish, purity, and rarity, are sought after as objects of dress and decoration. They form the principal part of the crown jewels of kings, not only from their beauty, but because they are supposed to comprize the greatest value in the smallest bulk; for a diamond, no larger than a nut or an acorn, may be the representative sign of the territorial value of a whole country, the equivalent in commercial exchange of a hundred fortunes, acquired by severe toils and privations.

Among these beautiful minerals mankind have agreed in forming a select class, to which the title of _gems_ or _jewels_ has been appropriated; while the term _precious stone_ is more particularly given to substances which often occur under a more considerable volume than _fine stones_ ever do.

Diamonds, sapphires, emeralds, rubies, topazes, hyacinths, and chrysoberyls, are reckoned the most valuable _gems_.

Crystalline quartz, pellucid opalescent or of various hues, amethyst, lapis lazuli, malachite, jasper, agate, &c., are ranked in the much more numerous and inferior class of ornamental stones. These distinctions are not founded upon any strict philosophical principle, but are regulated by a conventional agreement, not very well defined; for it is impossible to subject these creatures of fashion and taste to the rigid subdivisions of science. We have only to consider the value currently attached to them, and take care not to confound two stones of the same colour, but which may be very differently prized by the _virtuoso_.

Since it usually happens that the true gems are in a cut and polished state, or even set in gold or silver, we are thereby unable to apply to them the criteria of mineralogical and chemical science. The cutting of the stone has removed or masked its crystalline character, and circumstances rarely permit the phenomena of double or single refraction to be observed; while the test by the blowpipe is inadmissible. Hence the only scientific resources that remain are the trial by electricity, which is often inconclusive; the degree of hardness, a criterion requiring great experience in the person who employs it; and, lastly, the proof by specific gravity, unquestionably one of the surest means of distinguishing the really fine gems from ornamental stones of similar colour. This proof can be applied only to a stone that is not set; but the richer gems are usually dismounted, when offered for sale.

This character of specific gravity may be applied by any person of common intelligence, with the aid of a small hydrostatic balance. If, for example, a stone of a fine crimson-red colour, be offered for sale, as an oriental ruby; the purchaser must ascertain if it be not a Siberian tourmaline, or ruby spinel. Supposing its weight in air to be 100 grains, if he finds it reduced to 69 grains, when weighed in water, he concludes that its bulk is equal to that of 31 grains of water, which is its loss of weight. Now, a real sapphire which weighs 100 grains in air, would have weighed 76·6 in water; a spinel ruby of 100 grains would have weighed 72·2 in water, and a Siberian tourmaline of 100 grains would have weighed only 69 grains in water. The quality of the stone in question is, therefore, determined beyond all dispute, and the purchaser may be thus protected from fraud.

The _sard_ of the English jewellers (_Sardoine_, French) is a stone of the nature of agate, having an orange colour more or less deep, and passing by insensible shades into yellow, reddish, and brown; whence it has been agreed to unite under this denomination all the agates whose colour verges upon brown. It should be remarked, however, that the sard presents, in its interior and in the middle of its ground, concentric zones, or small nebulosities, which are not to be seen in the red cornelian, properly so called. The ancients certainly knew our sard, since they have left us a great many of them engraved, but they seem to have associated under the title _sarda_ both the sardoine of the French, and our cornelians and calcedonies. Pliny says that the _sarda_ came from the neighbourhood of a city of that name in Lydia, and from the environs of Babylon. Among the engraved sards which exist in the collection of antiques in the Bibliothèque Royale of Paris, there is an Apollo remarkable for its fine colour and great size. When the stone forms a part of the agate-onyx, it is called sardonyx. For further details upon Gems, and the art of cutting and engraving them, see LAPIDARY.

GEOGNOSY, means a knowledge of the structure of the earth; GEOLOGY, a description of the same. The discussion of this subject does not come within the province of this Dictionary.

GERMAN SILVER. See the latter end of the article COPPER.

GERMINATION; (Eng. and Fr.; _Das Keimen_, Germ.) is the first sprouting of a seed after it is sown, or when, after steeping, it is spread upon the malt floor. See BEER.

GIG MACHINES, are rotatory drums, mounted with thistles or wire teeth for teazling cloth. See WOOLLEN MANUFACTURE.

GILDING (_Dorure_, Fr.; _Vergoldung_, Germ.); is the art of coating surfaces with a thin film of gold. For a full discussion of this subject, see GOLD. Mr. Elkington, gilt toy maker, obtained a patent, in June, 1836, for gilding copper, brass, &c., by means of potash or soda combined with carbonic acid, and with a solution of gold. Dissolve, says he, 5 oz. troy of fine gold in 52 oz. avoirdupois of nitro-muriatic acid of the following proportions: viz. 21 oz. of pure nitric acid, of spec. grav. 1·45, 17 oz. of pure muriatic acid, of spec. grav. 1·15; with 14 oz. of distilled water.

The gold being put into the mixture of acids and water, they are to be heated in a glass or other convenient vessel till the gold is dissolved; and it is usual to continue the application of heat after this is effected, until a reddish or yellowish vapour ceases to rise.

The clear liquid is to be carefully poured off from any sediment which generally appears and results from a small portion of silver, which is generally found in alloy with gold. The clear liquid is to be placed in a suitable vessel of stone, pottery ware is preferred. Add to the solution of gold 4 gallons of distilled water, and 20 pounds of bicarbonate of potash of the best quality; let the whole boil moderately for 2 hours, the mixture will then be ready for use.

The articles to be gilded having been first perfectly cleaned from scale or grease, they are to be suspended on wires, conveniently for a workman to dip them in the liquid, which is kept boiling. The time required for gilding any particular article will depend on circumstances, partly on the quantity of gold remaining in the liquid, and partly on the size and weight of the article; but a little practice will readily give sufficient guidance to the workman.

Supposing the articles desired to be gilded be brass or copper buttons, or small articles for gilt toys, or ornaments of dress, such as earrings or bracelets, a considerable number of which may be strung on a hoop, or bended piece of copper or brass wire, and dipped into the vessel containing the boiling liquid above described, and moved therein, the requisite gilding will be generally obtained in from a few seconds to a minute; this is when the liquid is in the condition above described, and depending on the quality of the gilding desired; but if the liquid has been used some time, the quantity of gold will be lessened, which will vary the time of operating to produce a given effect, or the colour required, all which will quickly be observed by the workman; and by noting the appearance of the articles from time to time, he will know when the desired object is obtained, though it is desirable to avoid as much as possible taking the articles out of the liquid.

When the operation is completed, the workman perfectly washes the articles so gilded with clean water; they may then be submitted to the usual process of colouring.

If the articles be cast figures of animals, or otherwise of considerable weight, compared with the articles above mentioned, the time required to perform the process will be greater.

In case it is desired to produce what is called a dead appearance, it may be performed by several processes: the one usually employed is to dead the articles in the process of cleaning, as practised by brass-founders and other trades; it is produced by an acid, prepared for that purpose, sold by the makers under the term “deading aquafortis,” which is well understood.

It may also be produced by a weak solution of nitrate of mercury, applied to the articles previous to the gilding process, as is practised in the process of gilding with mercury, previous to spreading the amalgam, but generally a much weaker solution; or the articles having been gilded may be dipped in a solution of nitrate of mercury, and submitted to heat to expel the same, as is practised in the usual process of gilding.

It is desirable to remark, that much of the beauty of the result depends on the well cleaning of the articles, and it is better to clean them by the ordinary processes, and at once pass them into the liquid to be gilded. See GOLD, towards the end.

GIN, or _Geneva_, from _Genievre_ (juniper), is a kind of ardent spirits manufactured in Holland, and hence called Hollands gin in this country, to distinguish it from British gin. The materials employed in the distilleries of Schiedam, are two parts of unmalted rye from Riga, weighing about 54 lbs. per bushel, and one part of malted bigg, weighing about 37 lbs. per bushel. The mash tun, which serves also as the fermenting tun, has a capacity of nearly 700 gallons, being about five feet in diameter at the mouth, rather narrower at the bottom, and 4-1/2 feet deep; the stirring apparatus is an oblong rectangular iron grid, made fast to the end of a wooden pole. About a barrel, = 36 gallons of water, at a temperature of from 162° to 168° (the former heat being best for the most highly dried rye), are put into the mash tun for every 1-1/2 cwt. of meal, after which the malt is introduced and stirred, and lastly the rye is added. Powerful agitation is given to the magma till it becomes quite uniform; a process which a vigorous workman piques himself upon executing in the course of a few minutes. The mouth of the tun is immediately covered over with canvas, and further secured by a close wooden lid, to confine the heat; it is left in this state for two hours. The contents being then stirred up once more, the _transparent_ spent wash of a preceding mashing is first added, and next as much cold water as will reduce the temperature of the whole to about 85° F. The best Flanders yeast, which had been brought, for the sake of carriage, to a doughy consistence by pressure, is now introduced to the amount of one pound for every 100 gallons of the mashed materials.

The gravity of the fresh wort is usually from 33 to 38 lbs. per Dicas’ hydrometer; and the fermentation is carried on from 48 to 60 hours, at the end of which time the attenuation is from 7 to 4 lbs., that is, the specific gravity of the supernatant wash is from 1·007 to 1·004.

The distillers are induced by the scarcity of beer-barm in Holland, to skim off a quantity of the yeast from the fermenting tuns, and to sell it to the bakers, whereby they obstruct materially the production of spirit, though they probably improve its quality, by preventing its impregnation with yeasty particles; an unpleasant result which seldom fails to take place in the whiskey distilleries of the United Kingdom.

On the third day after the fermenting tun is set, the wash containing the grains is transferred to the still, and converted into low wines. To every 100 gallons of this liquor, two pounds of juniper berries, from 3 to 5 years old, being added along with about one quarter of a pound of salt, the whole are put into the low wine still, and the fine Hollands spirit is drawn off by a gentle and well-regulated heat, till the magma becomes exhausted; the first and the last products being mixed together; whereby a spirit, 2 to 3 per cent. above our hydrometer proof, is obtained, possessing the peculiar fine aroma of gin. The quantity of spirit varies from 18 to 21 gallons per quarter of grain; this large product being partly due to the employment of the spent wash of the preceding fermentation; an addition which contributes at the same time to improve the flavour.

For the above instructive details of the manufacture of genuine Hollands, I am indebted to Robert More, Esq., formerly of Underwood, distiller, who after studying the art at Schiedam, tried to introduce that spirit into general consumption in this country, but found the palates of our gin-drinkers too much corrupted to relish so pure a beverage.

GINNING, is the name of the operation by which the filaments of cotton are separated from the seeds. See COTTON MANUFACTURE.

GLANCE COAL, or anthracite, of which there are two varieties, the _slaty_ and the _conchoidal_. See ANTHRACITE.

GLASS (_Verre_, Fr.; _Glas_, Germ.); is a transparent solid formed by the fusion of siliceous and alkaline matter. It was known to the Phenicians, and constituted for a long time an exclusive manufacture of that people, in consequence of its ingredients, natron, sand, and fuel, abounding upon their coasts. It is probable that the more ancient Egyptians were unacquainted with glass, for we find no mention of it in the writings of Moses. But according to Pliny and Strabo, the glass works of Sidon and Alexandria were famous in their times, and produced beautiful articles; which were cut, engraved, gilt, and stained of the most brilliant colours, in imitation of precious stones. The Romans employed glass for various purposes; and have left specimens in Herculaneum of window-glass, which must have been blown by methods analogous to the modern. The Phenician processes seem to have been learned by the Crusaders, and transferred to Venice in the 13th century, where they were long held secret, and formed a lucrative commercial monopoly. Soon after the middle of the 17th century, Colbert enriched France with the blown mirror glass manufacture.

Chance undoubtedly had a principal share in the invention of this curious fabrication, but there were circumstances in the most ancient arts likely to lead to it; such as the fusing and vitrifying heats required for the formation of pottery, and for the extraction of metals from their ores. Pliny ascribes the origin of glass to the following accident. A merchant-ship laden with natron being driven upon the coast at the mouth of the river Belus, in tempestuous weather, the crew were compelled to cook their victuals ashore, and having placed lumps of the natron upon the sand, as supports to the kettles, found to their surprise masses of transparent stone among the cinders. The sand of this small stream of Galilee, which runs from the foot of Mount Carmel, was in consequence supposed to possess a peculiar virtue for making glass, and continued for ages to be sought after and exported to distant countries for this purpose.

Agricola, the oldest author who has written technically upon glass, describes furnaces and processes closely resembling those employed at the present day. Neri, Kunckel, Henckel, Pott, Achard, and some other chemists, have since then composed treatises upon the subject; but Neri, Bosc, Antic, Loysel, and Allut, in the Encyclopédie Méthodique, are the best of the elder authorities.

The window-glass manufacture was first begun in England in 1557, in Crutched Friars, London; and fine articles of flint-glass were soon afterwards made in the Savoy House, Strand. In 1635 the art received a great improvement from Sir Robert Mansell, by the use of coal fuel instead of wood. The first sheets of blown glass for looking glasses and coach windows were made in 1673 at Lambeth, by Venetian artisans employed under the patronage of the Duke of Buckingham.

The casting of mirror-plates was commenced in France about the year 1688, by Abraham Thevart; an invention which gave rise soon afterwards to the establishment of the celebrated works of St. Gobin, which continued for nearly a century the sole place where this highly prized object of luxury was well made. In excellence and cheapness, the French mirror-plate has been, however, for some time rivalled by the English.

The analysis of modern chemists, which will be detailed in the course of this article, and the light thrown upon the manufacture of glass in general by the accurate means now possessed of purifying its several ingredients, would have brought the art to the highest state of perfection in this country, but for the vexatious interference and obstructions of our excise laws.

The researches of Berzelius having removed all doubts concerning the acid character of silica, the general composition of glass presents now no difficulty of conception. This substance consists of one or more salts; which are silicates with bases of potash, soda, lime, oxide of iron, alumina, or oxide of lead; in any of which compounds we can substitute one of these bases for another, provided that one alkaline base be left. Silica in its turn may be replaced by the boracic acid, without causing the glass to lose its principal characters.

Under the title glass are therefore comprehended various substances fusible at a high temperature, solid at ordinary temperatures, brilliant, generally more or less transparent, and always brittle. The following chemical distribution of glasses has been proposed.

1. Soluble glass; a simple silicate of potash or soda; or of both these alkalis.

2. Bohemian or crown glass; silicate of potash and lime.

3. Common window and mirror glass; silicate of soda and lime; sometimes also of potash.

4. Bottle glass; silicate of soda, lime, alumina and iron.

5. Ordinary crystal glass; silicate of potash and lead.

6. Flint glass; silicate of potash and lead; richer in lead than the preceding.

7. Strass; silicate of potash and lead; still richer in lead.

8. Enamel; silicate and stannate or antimoniate of potash or soda, and lead.

The glasses which contain several bases are liable to suffer different changes when they are melted or cooled slowly. The silica is divided among these bases, forming new compounds in definite proportions, which by crystallizing, separate from each other, so that the general mixture of the ingredients which constituted glass is destroyed. It becomes then very hard, fibrous, opaque, much less fusible, a better conductor of electricity and of heat; forming what Reaumur styled _devitrified_ glass; and what is called after him, Reaumur’s porcelain.

This altered glass can always be produced in a more or less perfect state, by melting the glass and allowing it to cool very slowly; or merely by heating it to the softening pitch, and keeping it at this heat for some time. The process succeeds best with the most complex vitreous compounds, such as bottle glass; next with ordinary window glass; and lastly with glass of potash and lead.

Previous Next

Comments

A Dictionary of Arts, Manufactures and MinesChapter II: Application of Light-Gas (2)

0%34 min left in chapter