The latest form of storehouses tends to one of two extremes. Where land is
nearly level, and cheap, the greatest storage capacity can be obtained
with the greatest economy by means of a one or two story storehouse built
with a plank construction, with the beams secured to the posts by means of
knees. A traveling crane or railroad runs along the middle of the
storehouse, affording a ready means for rapid changes of the contents of
the storehouse.
Another form for storage is by means of very large brick buildings,
especially arranged as a protection against outside fire. In designing a
storehouse it is of especial importance that the stories should not be
made so high that it will be possible for a dangerous load to be piled
upon any one floor.
The wool storehouse of the Pacific Mills at Lawrence can be safely said to
be in its design and construction the finest example of mill engineering
in the country.
Another type of mill storehouse, designed for both raw material and
finished goods, is designed by Mr. John Kilburn, of Lowell, and consists
of two buildings placed at right angles to each other, and joining only
at one corner. These buildings do not contain openings through the floors
of any nature whatsoever, either for stairways, elevators, or any other
purpose; but all vertical communication is furnished by means of a masonry
tower at one corner of the buildings, which contains an elevator and
stairway. At the level of each floor, substantial balconies lead through a
doorway in the tower to one in the storehouse, and the storage is added to
or withdrawn from the storehouse in this manner.
I have not made any reference to the use of rolled iron for structural
purposes, because such material has not been used to any extent in mill
architecture. Irrespective of questions of space or of strength, wood
beams possess advantages in the reduction of vibration, facility of
securing the plank above and hangers below, and a great many other
purposes in the changing and alterations of a mill, which render them
peculiarly useful, and I believe that the results with Southern pine beams
in American mills are much superior to those of the iron beams in European
mills.
No small part of the success attending the use of rolled iron in the
structural purposes for which it is adapted, has been due to the excellent
and reliable engineering information contained in the manuals and
catalogues issued by the rolling mills. Such works are reliable and clear,
and, as far as I know, can without exception be safely followed.
The general tendency of American mill construction is toward as low
buildings as the price of land will admit. The American mills being
devoted to a large variety of operations, instead of being confined to a
single process after the manner of those of European type, require a great
deal more care in their organization, not merely in the original lay-out
for the purpose of arranging for the passage of the stock in processes
from the raw material to the finished product in as straight lines as
possible, but due consideration should also be given to providing
facilities for the enlargement of the mill.
As an illustration of the methods employed, in a paper mill plan of my own
design, [the view and plan being thrown on the screen], the various
operations containing processes of different hazard in regard to fire are
completely isolated from each other by means of fire walls, and the
storage of the mill is in turn isolated from the manufactory.
The storehouse consists of three sections, the largest section for paper
stock, which is sorted in the upper story, the second section, one story
in height, for other manufacturing supplies, and beyond the fire wall the
storehouse is arranged to contain the finished paper. Goods can be taken
away from or added to the storehouse at the single line of teams, or
railroad siding.
After the stock leaves the sorting room, it is carried to the dusting room
over a covered bridge, which is protected from the weather on one side,
yet does not form a flue for the spread of fire as does a closed bridge.
The first room in the main mill is used for a dusting room, and thence the
stock falls into the rotary bleach, whence it is carried through the fire
doors to the engine room. Here it meets the wood pulp and clay wheeled
from the middle section of the storehouse, which is on that same level.
After washing and beating, the stock is run into the drainers below,
whence it is raised again, and after suitable intermediate processes the
pulp is converted into paper on the paper machine in the connecting
building. This paper is then taken into the upper part of the main
building, and after being dried on the lofts is suitably calendered and
packed before being transferred into the extreme end of the storehouse to
await shipment.
At the present time it has been found that an inclined roof of the olden
type is not a necessity over a paper machine, as has been decreed by the
tradition passed down from old practices. Within the last year, a number
of flat roofs have been placed over paper machines, without any trouble
ensuing from condensed water forming on the ceiling and thence dropping
upon the stock. It is well known that the use of a flat roof in such
places is attended with a great many mechanical conveniences; and the
pitched roof hitherto used for these purposes has been submitted to, only
because it was presumed to be necessary. The whole tendency of mill design
is in the line of fitness of means to ends, in the simplest and most
direct manner.
When the mills in Lowell were first built, they consisted of isolated
buildings, which it was presumed would remain for all time; but when it
became necessary to increase the plant, it was found that the engineer had
wisely laid out the mills in the same yard in reference to a fixed grade,
so that corresponding floors would meet when the buildings were extended
so that they reached each other.
Wherever a strong and diffused light is necessary for any manufacturing
process, or the conditions are such as to require unusual stability of the
building, one-story mills lighted by monitors afford accommodations not
reached by any other form of construction.
In presenting before you some of the salient features of modern mill
construction, I have endeavored to show the various steps of progress
leading up to the development of the present types of design, as well as
some of the methods of construction in present use.
These various steps in advance, producing mills better suited for the
purposes for which a mill is built, are not generally due to elements
originating with the manufacturers, but with the Factory Mutual
Underwriters, who, finding it cheaper to prevent a fire than to settle a
loss, have in every manner encouraged improvements in construction,
equipment, and administration, with the result of diminishing the
insurance on textile manufacturing property during the last generation
from two and one-half down to one-fourth of one per cent., or reducing the
cost of insurance eighty per cent.
In designing any work, a careful regard should be given to precedents,
remembering that a good designer must also be a good copyist.
* * * * *
THE PASSIVE STATE OF IRON AND NICKEL.--E. Saint Edme.--The nickel of
commerce immediately becomes passive if immersed in ordinary nitric acid.
Iron, while being briskly attacked by common nitric acid, is rendered
passive by contact with nickel. If steel and nickel are plunged into the
acid together, the former metal is not even momentarily attacked. Nickel
retains energetically a proportion of combined nitrogen, to which its
passivity is due.