35y COMPRESSION. \%'J 



jRid which, after allowing for the counterpoise of the beam,, 

 gave a direct pressure of 8.1 cut ; and I could, at pleasure, 

 diminish tlic compressing force, by placing a bucket (e) at tiro 

 extremity of the lever, into which I introduced weights, whose 

 effect on the ultimate great mass, was known by trial. Many 

 barrels failed in these trials ; at last, I obtainied one of small 

 bore, inch 0.54-, which gave two good results on the 22d of 

 June 18 04-. 



No. 8. — Wishing to ascertain the least compressing force Trial of the 

 by which the carbonate could be etfectually constrained in |^,^^fo*j.p^'fo^^" 

 juelting heats, I first observed everything standing firm in a effectual con- 

 hcat of above 20° ; I then gradually threw weights into the ^'^\!b'^,^^te?nt'' 

 bucket, till tlie compressing force was reduced to 2 cwt. Till fused heat. It 

 then, things continued steady ; but, on the pressure being still ||j^^ on the" 

 further diminished, metal began to ooze out at the muzzle, round inch, «r 

 xvith me^x^asil>g rapidity. When the pressure was reduced to "[^g^gg"* '"*'^" 

 I^ cwt. air rushed out with a hissing noise. I then stopped 

 the experiment, by pouring water on the barrel. The piece 

 of chalk had lost 12 per cent. It was white and soft on the 

 outside, but firm and good in the heart. 



No. f). — An experiment was made with chalk, in a little Experiment 

 tube ; to this, one grain of water was added. I had intended eluded, 

 to work with 4 cwt. Only ; but the barrel was no sooner placed, 

 than an exudation of metal began at the muzzle, owing, doubt- 

 less, to the elasticity of the water. I immediately increased 

 the pressure to 6.1 cwt. by removing the weight from the 

 bucket, when the exudation instantly ceased, I continued the 

 fire for tlaree quarters of an hour, during which time no exu- 

 dation happened ; then all came out remarkably clean, vritlii 

 scarcely any contamination of metal. The loss amounted to 

 2.5Sperce/if. The substance was tolerably indurated, but 

 had not acquired the character of a complete stone. 



In these two last experiments, the bore being small, ii pyro- 

 meter could not be admitted. 



On the 5th of July 1S04, I made three very satisfactory ex- 

 periments of this kind, in a barrel with the large bore of 0,75 

 of an inch. 



No. 10. — was made with a compressing force of only 3 cwt. Expeiiments 

 A small eruption at the mu2zle being ob'icrved, water ^vas ^^'^.'J^^^^^^^'^'^* 



thrown 



