Steel Furnace^ — Invention of the Aremtter. 89 , ; 



changed, the hole is again clofed carefully to exclude the air ; but if, on the contrary, the 

 change be complete, the fire is extinguiflied, and the fteel is left to cool, for about eight 

 days more, when the procefs for making bliftered-fteel is finifhed. 



Fig. I, plate IV. is a plan of the furnace ; and fig. 2 is a fedion of it, taken at the line A B. 

 The plan is taken at the line C D. The fame parts of the furnace are marked with the fame; 

 letters, in the plan and in the feition. E E are the pots, or troughs, into which the bars of 

 iron are laid, to be converted. F is the fire-place. P, the fire-bars. And R, the afli-pit. 

 G G, &c. arc the flues. H H is an arch, the iniidc of the bottom of which correfponds with 

 the line 1 1 1 1, fig. I, and the top of it is made in the form of a dome, having a hole in the centre 

 at K, fig. 2. L L, &c. are fix chimnics. M M is a dome, fimilar to that of a glafe-houfe, 

 covering the whole. At N there is an arched opening, at which the materials are taken in 

 and out of the furnace, and which is clofely built up when the furnace is charged. At O O 

 there are holes in each pot, through which the ends of three or four of the bars are made to 

 projedl quite out of the furnace. Thefe are called tafting-bars, one of them being drawn 

 out occafionally to fee if the iron be fufficiently converted. 



The pots are made of fire-tiles, or fire-ftone. The bottoms of them are made of two courfes; 

 each courfe being about the thicknefs of the fingle courfc which forms the outfide of the pots. 

 The infides of the pots are of one courfe, about double the thicknefs of the outfide. The 

 partitions of the flues are made of fire-brick, which are of different thicknefles, as reprefented 

 in the plan, Sec. by dotted lines in the bottom of the pots. Thefe are for fupporting the fides 

 of the pots, and for directing the flame equally round them. The great object is to commu- 

 nicate to the whole an equal degree of heat in every part. The fuel is put in at each end of 

 the furnace, and the fire is made the whole length of the pots, and kept up as equally as 

 poflible. 



A^ 



XI. 



On the Origui of the Areometer, by Citizen EuSEBE SALfERTE*. 



lT the prefent moment, while Haflenfrantz is publifliing his intcrcfting memoirs upon 

 Areometry in your Journal *, it will, probably, be fomc gratification to your readers to receiv^ 

 fome information concerning the origin of the inftrument to which that fcience has given its 

 name. 



In the Encyclopedic methodique. Phyfique, I. 257, is the following paflage : *' It is com- 

 " monly thought, that the Areometer was invented about the end of the fourth century by 

 "' Hypacia, the daughter of Theo f, as we learn in the fifth letter of Synefius Cyreneus, in 

 « his fifth letter." 



* Annalesde Chimie, XXVII. 113. 



f Hypacia was a Platonic philofopher, eqvjally celebtated for her virtue, fcience, and beauty. The people' 

 of Alexandria, excited againft her by St. Cyril, flew her in the 41 5th year of the Chriftian era — S. 



Vol. Ill— May 1799, N Thi^ 



