‘ # : be eal 
188 Bibliography. : ," % 
= ; 
obtained from it; when moist, it yields a large quantity ; when dry, * 
very little. Dr. Jackson considers the 10 per cent. of water, as wa- 
ter of composition; but we have found that this coal, after lyinga — 
long time in a hot and dry garret, afforded very little gas at ignition, 
but gave abundance when moistened. The author is of the opinion 
that this coal will answer well for furnaces but not for parlor grates, 
as the ashes will form slag;.but he does not donbt that the mines 
may be profitably wrought, and that the coal exists in sufficient quan- 
titiy to justify thorough working of the mines. He has given very 
valuable comparative statements respecting the properties of the va- 
rious anthracites of our country, and has described particularly the 
mines of Mansfield, in Massachusetts, which are in the same geolo- 
gical formation, but our space does not permit us to quote these valu-— 
able remarks. We trust the time is not distant when the mines of 
Rhode Island and of Mansfield will be again explored, and with de- 
cisive advantage. 
Block Island, twenty five miles from Newport, and fifteen from 
Point Judith, isa very small territory with tertiary surface of granitic 
origin, and presents little that is interesting in geology beyond nume- 
rous peat beds, bog-iron ore, clays, sand and bowlders : the latter are 
of granite, and are identical with those on Point Judith and at Kings- 
ton, on the continent, while they rest on a substratum of blue clay, 
upon which they must have been deposited by diluvial causes—water 
and ice, aided by winds and currents. ‘There are no shells in the clays 
of this island, which sometimes form cliffs of seventy to one hundred 
feet perpendicular, while the hills rarely exceed one hundred and fifty 
feet above the sea level. There is no harbor—the. boats are drawn 
on shore by oxen when a storm is at hand; the sea washes away the 
land in some places, and the best defense is the long line of bowlders 
which fortify the coast, and repel the buffeting of the waves; 107 
move them would therefore be very injudicious. “3 
This island, with fifieen hundred industrious inhabitants, 1s fairly 
entitled to a breakwater, or artificial -harbor, to be erected at the 
pense of the general government. 
2 Some notice of the Agricultural part of Dr. Jackson's Report. 
This report is characterized by the extent of its agricultural obset- 
vations, and by the great number and accuracy of chemical analyses 
of soils, peats, limestones, and other substances of interest 1° the 
practical agriculturalist. Nearly two hundred of these analyses rad 
given, which have been perfurmed chiefly on the soils, &c. from Rhode 
Island. Dr. Jackson has not however in this report confined his t& 
searches exclusively to that state, but has sought for facts and infor- 
mation from the practical farmers of Massachusetts, and exam? 
soils fom various and widely different parts of the world, whenever 
s. 
/ 
ie 
