Vol. XXIV. No. 4.] 
POPULAE SCIENCE NEWS. 
53 
is very hard and tenacious, and is used to some 
extent in gas-fixtures. 
Aluminic oxide (Ah O3) is white when pure, but 
when colored with oxides of iron and manganese, it 
is known as enierj, and is used in the manufacture 
and grinding of cutlery. 
Aluminid hydrate (AU Oe He) is used to form 
lakes in dyeing. It acts sometimes as a base, and 
sometimes as an acid, and is thus interesting, 
because it fulfils Mendelejeft's prediction. 
Alum (K-2 Alv [S04]4 24 Ha O) is an important 
compound, formed by adding potassic sulphate to a 
boiling solution of aluminic sulphate, and crystal- 
lizing the alum from hot water. When pure, it 
crystallizes in white octahedrons, and so its purity 
may always be told by its crystallization. It is 
used extensively as a mordant in dyeing. 
Ultramarine is an aluminium compound. Its 
blue color is due to the way in which its constitu- 
ents are arranged, and not to those which it con- 
tains. It is a common blue pigment. 
Clay, as has been before stated, contains alum- 
inium. All pottery, earthen-ware, china, porcelain, 
etc., are made of clay. The clay is shaped by 
various processes, baked, and glazed. Aluminium, 
therefore, occurs in all pottery, etc. 
Although the compounds of aluminium are so 
widely distributed, the pure metal is comparatively 
rare. Many so-called cheap processes for making 
the metal have been discovered during the past 
fifteen years, but none have succeeded. Aluminium 
was formerly obtained entirely from the Aluminium 
Society of Paris, who make it from clay. Before 
the Franco-Prussian war, it Avas said that England 
and Germany could manufacture it, but during the 
siege of Paris none appeared. At that time no pro- 
cess was able to compete with that of the Society, 
who furnished aluminium at $1.25 per ounce troy. 
Jn 1882, about one ton of the metal was used in this 
country. In 1884, ^ Philadelphia chemist dis- 
covered a process, in which he substituted sodium 
\ apor for the sodic carbonate of the other processes. 
A better quality of metal was obtained, and many 
thousand ounces have been manufactured. 
The Cowles brothers have tried reducing alum- 
inium in an electric furnace. This is a sort of 
crucible, through which passes an electric current, 
flowing through a substance offering great resist- 
ance, and developing great heat. This fuses the mix- 
ture of charcoal and aluminium compound in the 
crucible, but it is very difficult to get the aluminium 
at this high temperature. A new process of reduc- 
tion has lately been discovered, by which, it is said, 
aluminium may be put on the market at $2.00 per 
pound, with the possibility of a much lowerprice. If 
this process is successful, the uses of aluminium will 
increase rapidly in a short time. 
Aluminium, being a fine conductor of electricity, 
a non-rusting, non-tarnishing metal, harder and 
much lighter than ir»n, must eventually replace 
iron. But, of course, the change will be gradual. 
Just as there has been a Bronze Age and an Iron 
Age, so there may be an Aluminium Age. Or, in 
other words, it will begin to be manufactured at a 
price which will make it useful in the arts. 
In many sections of the country, far away from 
cities and railroads, some of these old-time articles 
are still made in the original way. A visit to a 
"jug factory" in one of our interior counties will 
show an example of a primitive process still in 
active operation in a number of places. Many of 
our young people have probably not had an oppor- 
tunity of seeing how a jug is made. The writer 
remembers as a boy the apparent mystery as to how 
they were made, and was told that they were con- 
structed by plastering clay over a coil of rope, and 
the rope afterwards removed by uncoiling and with- 
drawing the same through the mouth of the jug. 
Such a method would, of course, be impracticable. 
The maker of pottery at one of these rude facto- 
ries is usually a small farmer, who devotes his spare 
time to the business. Since he uses his own mate- 
rial, employs no help, but does everything with his 
own hands, he cares nothing for strikes, freight 
rates, or labor agitators. His ware is good for so 
much per gallon in the vicinity or the neighboring 
country towns, where it is taken for sale on his own 
wagon. 
The potter sits astride a rough bench, and gener- 
ally uses an old, worn-out saddle to make the seat 
more comfortable. In front of him is a shallow- 
box, with a horizontal wheel or disc in the center, 
carried by an upright shaft having a similar, but 
heavier, wheel below and near the floor. He causes 
1 
1 
I 
[Origin.lI in Ptipular Scifnce yews.\ 
HOW JUGS ARE MADE. 
BY THOMAS C. HARRIS. 
The old-fashioned way of doing things is often 
lost sighl.of, and, when seen for the first time, is of 
great interest at the present day. To persons 
accustomed to large manufacturing enterprises, 
with special machinery for turning out certain 
articles very fast and cheaply, the hand-made 
article of an hundred years ago is curious and 
interesting. 
the wheel to revolve rapidly by means of a remark- 
ably simple foot-power arrangement, the heavy 
wheel at the bottom serving to keep up a steady 
movement. The foot-power is a short stick or rod, 
pivoted by a peg at one end, and suspended at the 
right height by a short piece of chain. The crank 
in the upright shaft is connected to the oscillating 
rod by a piece of wood. By a gentle side-way swing 
of his left foot, the operator produces the necessary 
rotary movement of his wheel. 
Having previously tempered his clay and sepa- 
rated it into parcels of the proper weight for a jug 
of a certain size, he takes one of the lumps and 
places it on the center of the revolving wheel, and 
proceeds to give it shape and form. It is a curious 
sight to watch the plastic material grow into sym- 
metrical shapes under the simple manipulations of 
the potter's fingers, sometimes assisted by simple 
tools of wood or bone. 
He first inserts one or two fingers of one hand 
into the center of the mass, and uses his other to 
press on the outside. This produces a hole in the 
i clay, which now assumes the shape of a thick ring. 
and is made thinner and drawn upwards, to form 
the side walls of the jug, by simply raising both 
hands at once, drawing the clay up between them. 
The article now has the form of a wide-mouthed jar 
or cylinder, ani may be finished as such by a few 
touches of a tool around the brim. To make it 
into a jug, the upper rim of the jar is turned 
inward with the hands, into the form of a dome, 
and the neck and lip shaped with one finger inside 
and a tool on the outside. The handle is shaped 
separately and attached by pressing the ends down 
on the moist body. At the bottom the jug is still 
stuck fast to the wheel, but is readily detached by 
drawing a fine wire under it. 
After being properly dried, the pottery is baked in 
a long arch of brick-work, having a chimney at one 
end. Wood is used for fuel, and, at the proper 
time, common salt is thrown in, to produce a glaze 
on the surface of the ware. Some skill and experi- 
ence is necessary to conduct the firing properly, or 
the ware fnay be ruined. Though often ungraceful 
in shape, this pottery is in common use in most 
places where the distance from large factories 
makes freight rates very high on such goods. 
STATE TELEPHONY. 
It is not yet known what action the Postmaster- 
General will take with regard to the telephone com- 
panies during the next six months. The companies 
work under a license from the Postmaster-General, 
who, at the end of June next, can give notice to the 
companies that the governinent intends to take over 
by purchase, the telephone service of the country. 
According to the draft license under which the cotu- 
panies carry on their business, the government may 
purchase the telephone systems at the end of this 
year by giving six months' notice, and it is very 
probable that this will be done, in view of the amal- 
gamation which recently took place between two or 
three of the companies. Should the State take over 
this industry it is to be hoped that we may be saved 
the inconvenience which has occurred in France 
since the French government took over the tele- 
phones a few months ago. There everything is 
topsy-turvy, and cointnunlcation between subscribers 
to the Exchange is exceedingly diflicult, and some- 
times impossible, owing prhicipally to the inatten- 
tion of the governtiient employes. Another great 
annoy.ince is the fact that many of the subscribers — 
especially those having the instruments in their 
dwellings — are rung up very early every morning by 
the employes, in order to see whether the transmit- 
ters are in working order. The Italian government, 
too, proposes to purchase the native telephones. 
We trust that we in England may be spared the 
vexations of the French subscribers, as telephonic 
communication is already carried on under suffi- 
ciently great difficulties. — Mechanical World {Eng- 
land.) 
.: ««•> 
LABORATORY NOTES. 
Action of Glycerine upon Vulcanized Rub- 
ber. — M. Morellet states that vulcanized rubber 
dipped suddenly into boiling glycerine takes the 
characters of non-vulcanized rubber, t. e , that its 
parts can readily Be joined and that it dissolves in 
the usual solvents of caoutchouc. The glycerine 
must be boiling at the time of first contact. 
Musical Flames. — The well-known experiment 
of making sounds by holding a tube over a jet of 
burning gas (usually hydrogen) is often omitted in 
chemistry classes because no suitable tubing is at 
hand. A fact noted by Mr. T. B. Smith is that a 
bottle will serve in place of a tube. A "philoso- 
pher's candle," properly burning, will yield a fine 
sound if capped by a wide-mouthed bottle, as a 
quinine bottle or large test-tube. 
