86 
GEORGIA BURR MILLSTONES. 
way, (the calcareous coating of animals,) m 
which lime exists in the secondary rocks. It is 
rare that it forms a reef by having been depos¬ 
ited in comparatively shallow water as a mud, 
carried down by streams, and depositing itself 
in a coat over the bottom of the sea. Some of 
the slate rocks of this state contain the lime 
in this condition, localised however, very much? 
that is, between the beds of true slate, at inter¬ 
vals of 100 to 200 feet, a bed of pure limestone 
mud is found, sometimes with shell remains, 
at other times without, varying from 10 to 25 feet, 
occasionally not more than 30 inches thick. The 
hydraulic limestone of this state is of this char¬ 
acter, termed in the survey of the state, the 
“Manlius water limestone,” an analysis of which 
made in the Laboratory of the American Agri¬ 
cultural Association afforded in 100 parts 
Silicates of alumina and iron 
insoluble in acid, 63.0 
Silica soluble in acid, 4.0 
Alumina, 4.5 
Peroxide of iron, 0.5 
Carbonate ol lime, 15.0 
Magnesia, ll.O 
Oxide and sulphuret of manganese, 2.0 
100.0 
What has been termed the “ Tully limestone,” 
a thin seam of pure workable stone, fit for build¬ 
ing and burning, which lies between the beds of 
slate, and stretches through Ontario, Yates, Sen¬ 
eca, Cayuga, and the other counties in a line 
eastward towards the Hudson, is also a bed of 
limestone mud, containing, however, a few shell 
fossils peculiar to it; two samples of which, 
taken 15 miles apart, analysed in the laboratory, 
yielded in 100 parts 
No. 1 
No. 2 
Insoluble silicates of alumina and iron, 
Alumina and peroxide of iron, 
Carbonate of lime, 
Magnesia, 
Manganese, 
Soluble salts as cloride of sodium, 
and sulphate of lime, 
Potash with traces of phosphoric acid, 
15.0 
23.0 
53.5 
2.8 
1.2 
trac’s 
4.0 
26.0 
60.0 
5.5 
1.0 
2.4 
1.0 
100.0 100.0 
In all of these may be perceived the large 
amount of clay and iron, which accompanies 
the carbonate of lime, as well as the proportion 
of insoluble silicates; all these being in very 
minute grains in the rock, showing the fine con¬ 
dition of muddy sand, of which it had been com¬ 
posed. It contains more than one half its total 
weight of carbonate of lime, and when burned 
without tgo violent, a heat, affords good lime. 
Whatever may be the true cause of this ab¬ 
sence of lime in the soil, of the fact there is no 
doubt, and its effect upon the growth of plants 
deserves our special consideration, which we 
shall take up in our next communication. 
GEORG-IA BURR MILLSTONES. 
Although this kind of stone has been known 
and used for a hundred years, it is like the dis¬ 
covery of the action of the water ram, or the 
well-known fertilising qualities of guano, which, 
though known for an equal length of time, re¬ 
quired the spirit that actuates the present age 
to bring it into general use. I had often heard 
of it, and sometimes heard it spoken of approv¬ 
ingly, and at other times with doubt, and often 
as of little value, and for the reason it was but 
little known or used. Stones made of French 
burr blocks were brought into the state in the 
almost immediate vicinity of the quarry, and 
millers contended, and still contend, that no 
other material exists that is suitable for mill¬ 
stones, except that of France. 
While at Savannah the other day, I sought 
the opportunity of examining this Georgia pro¬ 
duct, at the store of Messrs. Hoyt, agents of an 
association recently formed, called the “La¬ 
fayette Burr-Millstone Manufacturing Company,” 
who now have some 20 or 30 hands employed, 
and will soon increase the number to meet the 
demand. The quarry is 100 miles from Savan¬ 
nah, and six miles from the Macon Railroad, 
upon the plantation of P. B. Connelly, extending 
over a tract of about 1,700 acres, near the line 
of Jefferson and Burke counties. Previous to 
the time the present proprietors commenced, in 
1849, about a thousand pair of millstones had 
been made, and although many of them in a 
rough manner, and the blocks not so carefully 
selected as at present, yet, not one has ever 
been known to be discarded, and generally they 
have been highly approved. Still, as the opin¬ 
ion has prevailed that nothing but French burr 
would make good wheat flour, this invaluable 
quarry has laid almost idle and worthless up to 
the past year or two. The quantity is inex¬ 
haustible. It is generally near the surface, but 
the ground is considerably broken by creeks 
and ravines, and the veins of grit are from six 
to twenty feet thick. There are excellent sites 
for mills, where the power of water might be 
used for shaping the blocks, with machinery 
lately invented for cutting stone. 
The face of the blocks, when dressed, shows 
a surface quite as open as French burr, free 
from all loose pebbles, sand, iron nodules, and 
veins. In fact, the cavities when examined with 
