atmospheric air, and the muriatic acid comes off in large quantities, which, if allowed to escape into the atmosphere, would be very deleterious both to life and vegetation. By the power of the jets, this gas is drawn into an horizontal chimney, which runs along from the furnace till it comes to a square perpendicular tower, 25 feet high, and which is divided down the middle by a partition, and filled with broken coke. This tower has water discharged into its top, at the rate of about 20 gallons per minute. The jets not only draw the gas and smoke along the horizontal chimney, but up to the top of the tower through the stream of falling water, then down the other side of the partition, and thence through as many cones as jets (each cone being 1 foot long, 9 inches diameter at the base and 4 inches at the apex), into a passage in which they are inserted, and which runs along like a drain under the surface of the ground for about 100 yards. The object that the Messrs. Swinbourne had in view when they introduced the steam jet into their works, was to condense the noxious muriatic acid gas, and at the same time to ventilate the furnaces in the most perfect manner. So much is this done, and so perfectly, that a chimney about 200 feet high is entirely superseded for these purposes. When this chimney was used, the imperfect ventilation of the furnaces and condensation of the gases were such, that it frequently cost the works £300 a year, for damages to vegetation, caused by these gases. At the Don Alkali Works, on the Tyne, a boiler, 20 feet by 5, with a pressure of 30 lbs. to the inch, its steam driven through jetsths of an inch, or thereabouts, directed through cones whose apexes are only 4 inches in diameter, produces a white heat in the furnaces, and draws along through the horizontal passages and then up a tower 40 feet high, filled with coke and falling water, the whole smoke and muriatic acid gas. The distance is not less than 150 yards before they reach the place where the jets are acting. The gas is thus condensed to the amount of nearly 50 tons a week, and, P instead of going to destroy vegetation, as it formerly did to the cost of the manufacturers, when chimneys for ventilation were used, it now goes to form bleaching powder, and is one of the most valuable, instead of being one of the most injurious products of the manufactory. The deleterious hydrochloric acid, driven off in the above chemical process in such abundance, requires to be disposed of without touching animal or vegetable life. If it be thrown into the atmosphere at certain elevations, its specific gravity being upwards of one-fourth more than that of the air, it descends upon the earth in large volumes, affecting life and vegetation. As water absorbs nearly 500 times its own bulk of this gas, the steam jets, in the above processes, force the gas, by a powerful ventilation, up through the large descending column of water in the condensing towers. The absorption in this operation is nearly complete, and what may pass free is absorbed by the steam, after it passes the jets in the horizontal chimneys. The exit in the yard of the manufactory scarcely shows, in the escapage, the slightest vestige of the acid. The chimneys, which the manufacturers of alkali have had erected sometimes 400 feet high, at a cost of from £2000 to £3000, as in the Tyne works, may for the future be saved by the adoption of the steam jet, which does its work not only more economically, but more efficiently than those costly fabrics. This process, effected by the steam jet, is suggestive of horizontal chimneys for manufactories, for the purpose of preventing smoke or other obnoxious effluvia from vitiating the atmosphere of towns; and, also, for the ventilation of town sewers and the destruction of their gases. One of the northern mines, possessing nearly as many miles of passages, and filled with as deadly gases as the sewers of London, is kept perfectly free from these gases, and in a state fitted for the daily operations of the miners, by the steam jet. N. Logarithm. N. Logarithm. N. Logarithm. 1.01 0099503 1.41 3435897 1.81 5933268 1.02 0198026 1:42 3506568 1.82 5988365 1.03 0295588 1.43 3576744 1.83 6043159 1.04 0392207 1.44 3646431 1.84 6097655 1.05 0487902 1:45 3715635 1.85 6151856 1.06 0582689 1.46 3784364 1.86 6205764 1.87 6259384 1.88 6312717 3987761 1.89 6365768 4054651 1.90 6418538 1.13 1.14 1.15 1.11 1043600 1.51 1.12 1133287 1.52 1222176 1.53 1310283 1.54 •1397619 1.55 4121096 1.91 6471032 4187103 1.92 6523251 4252677 1.93 6575200 4317824 1.94 6626879 4382549 1.95 6678293 1.16 1484200 1.56 4446858 1.21 •1906203 1.61 4762341 2:01 1.26 •2311117 1.66 5068175 2.06 .7227059 1.27 2390169 1.67 5128236 1.28 •2468600 1.68 5187937 1.29 ⚫2546422 1.69 5247285 1:30 •2623642 1.70 ⚫5306282 2.07 7275485 2.08 7323678 2.097371640 2:10 7419373 1.31 2700271 1.71 5364933 Logarithm. N. Logarithm. N. Logarithm. .9593502 3:01 1.1019400 ⚫9631743 3.02 1.1052568 9669838 3:03 1.1085626 -9707789 3.04 1.1118575 9745596 3.05 1.1151415 N. 2.21 7929925 2.61 2-22 7975071 2.62 2.23 8020015 2.63 2.24 8064758 2.64 2.25 ⚫8109302 2.65 2.36 8586616 2.76 10152306 || 3.16 1.1505720 2.37 8628899 2.77 1.0188473 3.17 1.1537315 2:38 8671004 2.78 1.0224509 3.18 1.1568811 2.39 -8712933 2.79 1.0260415 3.19 1.1600209 2:40 8754687 2.80 1.0296194 3.20 1.1631508 2.41 .8796267 2.81 1.0331844 3.21 1.1662709 2.42 .8837675 2.82 1.0367368 3.22 1.1693813 2:43 ⚫8878912 2.83 1.0402766 3.23 1.1724821 2.44 ⚫8919980 2.84 1.0438040 3.24 1.1755733 2.45 •8960880 2.85 1.0473189 3.25 1.1786549 2.46 ⚫9001613 2.86 1.0508216 3.26 1.1817271 2.47 .9042181 2.87 1.0543120 3.27 1.1847899 2.48 9082585 2.88 1.0577902 3.28 1.1878434 2.49 9122826 2.89 1.0612564 3.29 1.1908875 9162907 2.90 1.0647107 3:30 1.1939224 2.50 2.51 9202827 2.91 1.0681530 3.31 1.1969481 2.52 9242589 2.92 1.0715836 3.32 1.1999647 2.53 9282193 2.93 1.0750024 3.33 1.2029722 2.54 •9321640 2.94 1.0784095 3.34 1.2059707 2.55 9360933 2.95 1.0818051 3.35 1.2089603 2.56 ·9400072 2.96 1.0851892 3.36 1.2119109 2.57 9439058 2.97 1.0885619 3.37 1.2149127 2.58 ⚫9477893 2.98 1.0919233 3.38 1.2178757 2.59 •9516578 2.99 1.0952733 3.39 1.2208299 2.60 9555114 3.00 1.0986123 3.40 1.2237754 N. Logarithm. N. | Logarithm. N. Logarithm. 3:41 1.2267122 3.81 1:3376291 4.21 1.4374626 3.42 1.2296405 3.82 3.43 1.2325605 3.83 3:44 1.2354714 3.84 3:45 1.2383742 3.85 13480731 4.25 1.4469189 1:3402504 4.22 1.4398351 13428648 || 4.23 1.4422020 1.3454723 4.24 1.4445632 3.46 1.2412685 3-86 1.3506671 4.26 1.4492691 3.47 1.2441545 3.87 1:3532544 4.27 1.4516138 3.48 1.2470322 3.88 1.3558351 4.28 1.4539530 3.49 1.2499017 3.89 1:3584091 4.29 1.4562867 3.50 1.2527629 3.90 13609765 || 4:30 | 1:4586149 3.51 1.2556160 3.91 1:3635373 4:31 1·4609379 3.52 1.2584609 3.92 1.3666916 4.32 1.4632553 3.53 1.2612978 393 1.3686394 4:33 1.4655675 3:54 1.2641266 3.94 13711807 4:34 1:4678743 3.55 1.2669475 3.95 1.3737156 4:35 1:4701758 3:56 | 1.2697605 3.96 1.3762440 4.36 1:4724720 3.57 1.2725655 3.97 1.3787661 4:37 1-4747630 3.58 1.2753627 3.98 1.3812818 4.38 1-4770487 3:59 1.2781521 3.99 13837912 4:39 1.4793292 3.60 1.2809338 4:00 1.3862943 4:40 1.4816045 3.61 1.2837077 4.01 1.3887912 4:41 1.4838746 3.62 1.2864740 4.02 1.3912818 4:42 1.4861396 3.63 1.2892326 4.03 1.3937663 4:43 1.4883995 3.64 1.2919836 4.04 1.3962446 4.44 1.4906543 3.65 1.2947271 4.05 1.3987168 4.45 1.4929040 3.67 3.66 1.2974631 || 4:06 1.4011829 4.46 1.4951487 1.3001916|| 4:07 | 1.4036429 4.47 1.4973883 3.68 1.3029127|| 4:08 1.4060969 4:48 1.4996230 3.69 1.3056264 4.09 1.4085449 4:49 15018527 3.70 1.3083328 4.10 1.4109869 4.50 1.5040774 3.71 13110318 || 4.11 1.4134230 4.51 1.5062971 3.72 1.3137236 || 4:12 1.4158531 4.52 1.5085119 3.73 13164082 4.13 1.4182774 4:53 1.5107219 3.74 13190856 4.14 1.4206957 4.54 1.5129269 3.75 13217558 4.15 1.4231083 || 4.55 1.5151272 4.57 1.5195132 3.76 13244189 4.16 14255150 4.56 1.5173226 3.77 1.3270749 || 4·17 | 1.4279160 3.78 1.3297240 4.18 1.4303112 || 4:58 1.5216990 1.5238800 3.79 1.3323660 4.19 1.4327007 || 4:59 3.80 1.3350010 4.20 1.4350845 4.60 1.5260563 |