APPENDIX. 337 
the Tube, which is the (ame thing as if the 
Tube was nine times as long, therefore the 
Air in the globofe Veffel, will not be forced 
within the Capacity of the Tube, till the 
Veffel has defeended to the Depth of nine 
Columns, or nine times thirty three Feet ; 
for then the Air will be compreffed within 
one tenth of the Space it at firfl: took up. 
5>. Suppofing therefore the Inftrumcnt to 
have defeended to the Depth of ninety nine 
Columns of Water, or ninety nine times 
thirty three Feet, viz, Feet, then the 
Air will be compreffed within part of 
five hundred Inches (for the Capacity of the 
whole Veffel was fuppofed equal to a Tube 
of that length) that is, within five Inches of 
the Top of the Tube; and confequently the 
Rod will be found tinged with the coloured 
Oil within five Inches of its Top. 
lo. Suppofe again the Inftrument to have 
defeended to the Depth of a hundred and 
ninety nine Columns of thirty three Feet 
each, then the Air will be compreffed within 
the ^th part of the whole, that is, nearly 
within two and half Inches of the Top of 
the Tube. In this Cafe the Inflrument will 
Z have 
