150 
POPULAR SCIEIsTCE NEWS. 
[October, 1890. 
matter they contain, these are then called blackband 
ores. They yield generally about 35 per cent, 
of metallic iron. 
Of the oxides of iron, the most important are the 
magnetites, and the red and brown hematites. 
Magnetite, so called from its magnetic property, 
which has also given it the name lodestone, is one 
of the richest of iron ores, and contains when 
purest, 7241 per cent, of iron. It is generally found 
combined with a gangue of silica, lime, alumina, 
and sometimes, also, very small quantities of sulphur 
and phosphorus. It is most often iron black in 
color, yielding a black streak, and occurs in granite, 
gneiss, clay slate, hornblende schist, and limestone, 
often in company with the hematites. 
Red hematite is most commonly found in one 
of four forms which are severally known as specular 
iron, micaceous ore, kidney ore, and red ochre. 
The specular is a crystalline variety of a steel grey 
color, often called from its long, hexagon-shaped 
crystals, needle ore. The micaceous variety occurs 
in the form of tliin sheets or scales of a reddish- 
brown color. Kidney ore occurs as dark brownish- 
red botryoidal and kidney-shaped concretions, often 
with smooth and lustrous surfaces. Red ochre is a 
soft, earthy variety of this oxide, and has most value 
as a pigment, though used also in puddling furnaces. 
A less common variety is known as fossiliferous 
ore, from the small fossil shells it contains, on 
account of the lime in which, it is self-fluxing. 
The gangue of these ores consists largely of silica, 
and is comparatively free from sulphur and phos- 
phorus. Their yield of metal is from 50 to 70 per 
cent. They are usually found in the older geologi- 
cal formations, particularly the Trenton limestones. 
Brown hematite, common forms of which are 
limonite, pot iron, and bog iron ore, yields about 60 
per cent, of metallic iron when most pure, but these 
ores vary very mucii, both as to the quantity of pure 
iron they contain, and as to the constituents of their 
gangues. Sulphur, phosphorus, manganese, and 
silica are usually present, but in no fixed propor- 
tions. The brown hematite deposits are generally 
found in the clay above the subcarboniferous lime- 
stones, usually of a sedimentary character forming 
beds of ore, but sometimes, especially in the older 
formations, existing in veins. 
The United States at present produces about one- 
fourth of the iron ore of commerce, or about 
12,500,000 gross tons. Of this, the Lake Superior 
region at present furnishes the most, chiefly red 
hematite and magnetite. Pennsylvania, with its 
soft magnetites and carbonates, is the next impor- 
tant source of supply. New Jersey and the Adiron- 
dack and Lake Chaniplain regions are also prolific 
sources of magnetites, and Missouri furnishes large 
quantities of red hematites, chiefly in the form 
of specular iron ore. In Virginia, North Caro- 
lina, Georgia, Alabama, Tennessee, and Kentucky, 
increasingly large quantities of ore are mined 
yearly, and of this, about 70 per cent, is red 
hematite, 25 per cent, brown hematite, and 5 
per cent, magnetite. And it will probably not be 
many years before these States constituting the 
New South will be the principal source of the 
world's iron supply. 
STEEL RAILWAY TIES. 
Experiment is being made by the Delaware and 
Hudson Railroad Company to test the adaptability 
and superiority of steel ties for railroad uses. On 
a section of the road leading south from Ballston 
for nearly half a mile, the wooden sleepers have 
been removed and the track reconstructed with the 
steel ties. So far they give good satisfaction. As 
trains pass rapidly over this piece of road, a peculiar 
buzzing noise is noticeable, also the vibration 
caused by the wheels upon the rails is observably 
greater; but it is also the smoothest and pleasantest 
riding piece of road between Troy and Saratoga. 
The test of the safety and adaptability of the steel 
ties is being made under the supervision of A. J. 
Swift, chief engineer of the road, and the^' will be 
adopted or rejected upon his recommendation. 
So far he regards the steel ties as a success ; but 
no more will be laid until those now in use have 
had the test of the winter to see in what manner, 
if any, they will be affected by ice, frost, and snow, 
and if they are equally safe in clay and quicksand 
and gravel. If they stand ail these tests, Mr. Swift 
has no doubt of the steel ties being speedily adopted 
for general use as the old wooden sleepers need to 
be replaced. The objection of their greatly in- 
creased first cost is fully met and overcome by their 
durability. Of their greater safety, if they stand 
the test, there can be no doubt, as by their use it is 
impossible for the rails to spread or in any other 
manner to become displaced. They also give to the 
track the perfect efl"ect of a continuous rail. The 
steel ties are in shape an inverted "T." They are 
seven feet long, seven inches wide, and are laid 
twenty-two inches apart from centers. At either 
end of the tie is a socket, in which is laid a block 
of wood, four by five inches square and about sixteen 
inches long, and upon which the rail is laid and 
firmly held in place. — Scientific American. 
INDUSTRIAL MEMORANDA. 
To Solder Pin-holes in Platinum Vessels. — 
A ready means is suggested by Mr. Piatt in the 
Journal de Pharmacie et de Chimrie for soldering the 
minute pin-holes which occur in old platinum 
vessels which have been in long use. A few milli- 
grammes of chloride of gold are placed over the 
flaw, and warmed to fusion. The fused mass is then 
heated in the flame of an oxyhydrogen blowpipe, 
when the gold salt is reduced to the metallic state, 
leaving a neatly soldered spot. 
A Remarkahle Accident. — A man employed 
in the chlorate of potash department of Messrs. 
Muspratt's works, at Flint, Wales, was entering the 
premises when he struck a light against his trousers. 
The wearing apparel was so impregnated with chlo- 
rate dust that it ignited instantaneously, and he 
was immediately enveloped in a mass of flame. A 
fellow-workman promptly threw him into a pool 
of water, but when extracted it was found that he 
had been so fearfully burnt that no hopes are enter- 
tained of saving his life. 
Catling's Cast Steel Gun. — Dr. Gatling has 
invented a new steel gun, which he claims will be 
far superior to the built-up gun, and can be made at 
half the cost. The patents consist of making guns 
cast from the highest grade of steel to shape around 
a central core. This central core is utilized for the 
purpose of cooling the casting from the interior 
while the exterior is still hot. The cooling process 
thus begins from the interior and works out, directly 
the reverse of the ordinary way. The metal is 
forced, as it were, from the interior outwardly, 
thereby avoiding the creation of a hard, resisting 
arch on the exterior of the casting, at which point 
the full intensity of the high power force exercised 
by the exploding ingredients within the gun exerts 
itself. It makes the interior of the gun, where the 
greatest strain Is felt, the toughest and hardest part, 
and the soft and spongiest part the exterior, which 
thus ads somewhat after the manner of a cushion. 
This is directly the reverse of the old style guns, 
in which the spongiest part is on the interior. 
Another important point is the method in which 
the metal is cast. A revolving motion is given it, 
which makes the grain spiral. 
Tlje Out- Door «Ioiid. 
Edited by HARLAN H. BALLARD, 
President op the Agassiz Association. 
[P. O. Address, Pittsfield, Mass.] 
ON THE SHORES OK LAKE QUINSIGA- 
MOND. 
.One of the best places in the world for a boy 
to spend the summer is at the Natural History 
Camp at Lake Quinsigamond. If any boy does 
not know where this lake is, and all about its 
beauty, it is because he isn't old enough to be 
interested in boating, for everybody knows that 
many a famous college race has been rowed on its 
smooth and glistening waters. It is three miles 
from the city of Worcester, in Massachusetts, and is 
reached by a busy little narrow-gauge railway, over 
which open cars run merrily back and forth every 
hour — and I don't know but every half hour — in the 
day. 
history of the camp. 
A few years ago. Dr. Raymenton, of the Worces- 
ter Society of Natural History, conceived the idea 
of establishing a summer camp for boys on the 
shore of this lake. Other members of the society 
became interested, and also many gentlemen of 
Worcester and prominent educators and lovers 
of boys everywhere. Mr. E. W. Forbush is now 
President of the institution. Many persons shook 
their heads doubtfully at first, and began to talk 
about all the difficulties and dangers of the plan. 
Where would the money come from ? Would boys 
care to go.' Suppose they should be taken sick 
miles away from a physician? Could discipline be 
maintained .' Would it be good for boys to study so 
hard in the summer.' Wouldn't they get drowned? 
How would they be interested evenings? What 
about Sundays? Such were some of the questions 
raised by the croakers, and it seemed for a time as 
if they could actually invent two equally difficult 
conundrums while the favorers of the plan were 
solving one. But, fortunately, as each question 
arose it was answered so wisely that it staid 
answered, and by and by the doubters found it so 
hard work to imagine any more evil possibilities 
that they got tired of trying, and admitted that after 
all the camp was a good thing and a great success. 
The President of the Agassis Association was 
invited by Mr. Kelley, one of the managers of the 
camp, to go to Worcester and talk to the boys about 
local societies for the studyof natural history. The 
invitation was accepted, and the time for the address 
was fixed for June 24, the day of the formal open- 
ing. At the appointed time the pretty pavilion bv 
the lake was crowded by an earnest audience, com- 
posed of campers and their friends, who were all 
greatly interested to hear of the many enthusiastic 
bands of boys and girls who are engaged in studying 
natural science at their homes under the banner 
of the Agassiz Association. But the speaker was 
more interested in using his eyes and ears than his 
lips, for he had never before seen so good a solution 
of the question, "What shall we do with our bovs 
in the summer?" 
THE BOAT-RIDK TO CAMP. 
The narrow-gauge railroad, already mentioned, 
ends at a point on the lake about two miles from the 
camp. Here a pretty steam yacht was found, just 
ready to start for camp. Several handsome, vigor- 
ous boys and young men were stepping aboard. 
They were clothed in a dark blue uniform, and had 
on their caps the letters "N. H. C." 
" So it seems you have a little military drill?" 
"Oh, yes; just enough for regularity and exer- 
cise." 
