384 Hf. Engelmann on vegetation known as 
master’s hand, and not only the deduction of the fundamental 
and most convenient formulas, but also the distinctions between 
the various quantities so easily confounded under the general 
0 r” or “mean error,” are made so clear 
and manifest that the — cannot appear to the student as 
either abstruse or confusin 
This appendix is by no means a compilation ; it is an original 
treatise in which previously known formulas are deduced ina 
new order from the author’s own stand-point. Peirce s Criterion 
for the rejection of doubtful observations is given, together with 
a very simple ee a by the author, which agrees 
nearly with that of Pei 
In conclusion, we desiakd call attention to the intrinsic eyes: 
oe the sree treatise, as including a wide eld, and not only 
ting to each department its own appropriate degre of 
—e x be of the most convenient application, theo- 
etical accuracy of processes and formulas, practical knowledge 
of macsieieeins in short, the requisite, now fulfilled for the first 
time in a text-book on Practical Astronomy, that the author 
should be both a mathematician and an observer, all unite to 
make this new production of Prof. Chauvenet a classic of the 
highest order, and an invaluable contribution to astronomical 
science. 
Art, XXXIII.— Remarks upon the causes producing the dient 
characters of — known as Prairies, Flats, and Barrens m 
Sor special reference io observations made in 
Perry and ey uate by Henry ENGELMANN, 2 
State oe peter 2 
and, 0 on a different sil, the @bstooak land sik 
_ The prairies in this istrict nieoeaciab lp: occupy. the bigne it 
d, but their relative elevation varies considerably. 
lo pcerlemet a scoot shes tonele tn within 0, nye 
