52





[Manhattan]





RECORD AND   GUIDE.





January lo, 19037





rises from it is directed by the flre brick arch down to and over
the brightly burning coal beyond. At the same time the plate,
hanging loosely In the ash pit, cuts ofC some of the air from the
rear portion of the flre, while It Increases the proportion of
oxygen which passes through the front part and which the smoke
carries with it to the rear, where the heat Is sufficient to deter¬
mine combination. This simple arrangement seems to have proved
very successful. Although the flrebrick arch, of course, cuts off
the front part of the water tubes from the direct action of the
fire the loss in evaporating power due to this is said to be fully
made up by the more perfect combustion of the fuel, while the
arch, by protecting the front ends of the tubes and their connec¬
tions from violent fluctuations of heat, and from the currents of
cold air which enter when the flre doors are opened, favors con¬
stancy of pressure and preserves the tubes and joints. On the
first Installation of the apparatus in a battery of boilers in the
Avenue Breteuil, while the smoke was practically suppressed, it
was found that more coal was used by about five per cent, than
was burned without it. The difference was, however, discovered
to be due to the loss of small particles of coal through the grate
In shifting the charges from the front to the back of the fire;
and, as "Le Genie Civil" tells us. It was substantially overcome
by changing the grates and putting In those of the Wagner pat¬
tern, the bars of which are only one-quarter of an Inch apart.





The Development of  Rolled  Beams.

There were so many engineering triumphs during the nineteenth
century and there are so many champions to uphold the suprem¬
acy of particular examples, it is not surprising that their rela¬
tive VE-lue has not been established. But as regards statical con-
strrction nothing arose during the century to surpass the de-
teimlnation of the iorms of beams and columns. Previous to
1820, the forms which were in use would now be considered as
alrturd. The limitation of the resistance to extension offered
by cast Iron was an obstacle to its general employment for beams.
The elaborate arid costly experiments in Great Britain of Hodg-
kinson and Fairhairn, which were confirmed by those ordered by
Robert Stephenson, to discov&r the most suitable form for a
wrought-iron beam which would serve ais a substitute for cast
iron, were crowned with success. It was established beyond
doubt, that with two horizontal flanges united by a web a beam
was produced of which the strength could be calculated before¬
hand, and which was not liable to the uncertainties or accidents
that diminished fhe confidence in the use of cast iron. The
flanges might take the form* of a series of cells or chambers and
the web might become a framing of struts and ties, but the prin¬
ciple of a great structure like the Britannia Bridge was identical
with that of a small girder made up of angle-irons and plates and
which could be utilized" for a factory floor or for a bridge over a
lane. From that apparently simple conclusion ctructures have
become possible which have not only revolutionized the practice
of bridge building, but have enabled civil engineering to accom¬
plish its main purpose of facilitating communication between
men.

The simplicity of the normal wrought-iron beam was an In¬
ducement to inventors to devise arrangements for Its production
by rolling. If angles, tees and channels could be turned out in
unlimited quantities, why should not a form which might be de¬
scribed as a double tee or a quadruple angle-iron with a web be
also feasible? Various sections of rails could be rolled, and why
not I-beams or joists?' A strike of carpenters in Paris had ex¬
tended the use of iron, and, moreover. English architects began
to realize the advantage of having floors which resembled the
French, and in which rolled iron was an element The produc¬
tion of joists was therefore quickened, but for a long time the
sections were limited in their dimensions. An increase of size
was effected with difficulty. Twenty years ago the great Cock¬
erill Company in Belgium rolled no larger sections than 12^^;
inches by G'/i inches for iron, and 8% Inches by 4 inches for steel.
The biggest steel joist which has been available in Europe up to
the present measures 20 inches by TVi inches, although In
America we have 24 inches by 71-^ Inches. The difficulty is
as much with the width of the flanges' as with' the depth. As a
rule the flanges were supposed to measure one-half the length,
and thus such proportions as 12 inches by 6 inches, 10 Inches by
■5 inches, S inches by 4 inches, G'inches by 3 Inches, have become
familiar among builders. After a certain limit the proportion is
diminished—10 by 0, 14 by 0 and 17% by 6% are recognized
market sections.                 •      '.     '

The inefficiency arising from the inadequacy of small size sec¬
tions was overcome. Plates have been added to increase the
width of joists, and two or more have been rivetled together in
order to obtain the desired height. At one time it was generally
accepted that for all girders which exceed 12 inches in depth it
was economical to construct thenrx of-plates and angle-irons, but
In a great many cases there is not sufficient time for the building
up of beams.   ;>■   i   '    -•

What we have'sard is of course familiar to our readers, but it
will help to explain'the satisfaction in which every growth In
size of rolled joists is received. The whole history of the world.
it has been stated, would have been altered if Cleopatra's nose
had been an inch longer or shorter. The possibility of being able
to obtain a 24-inch instead of a 20-inch girder may have an im¬
portant influence In fixing the character of a building.   What,





then, is to be said of an improvement in rolling mills by which
30-Inch girders can be as easily procured as 7-inch joists were at
one time,? The advantages would be difficult to estimate on ac¬
count of their vastness.

---------------------1--------------------

Duties  of  an Architect  in   England.

In an address delivered before the Architectural Association of
England, in a meeting in London, In 11)01, the following line of
duty was mentioned as the usual services recognized among the
profession:

1. Reasonable preliminary sketches in pencil, revised until the

wishes of the client are perfectly ascertained.

2 An approximate estimate of cost, such as may be obtained
by cubing.

3.  Preparation of a full set of drawings to one-eighth scale-
complete in all respects, with one traced copy of the same for
the use of the builders in carrying on the works.

4.    A complete detailed speclflcatlon, with conditions of con¬
tract, the same to be in duplicate—one copy being for use of
builder,

5.   Advertising and obtaining tenders for the work if let by con¬
tract.

6.  Complete details, sufficient for the ordinary workman in
each trade to execute his portion of the building. This to mean
% or Yi scale drawings of the better class of work, and half and
full-size sections of all moldings and more delicate parts; also
full and explicit instructions for the proper execution of the work
should be given in al! cases.

7.   Personal supervision by the architect or his deputy should
be made monthly, or once in six weeks, dependent upon size of
building.

Traveling expenses, extra copies, surveys, taking out quanti¬
ties extra.

------------*------------

Coal   Briquettes  in   Germany.

The manufacture and use of briquettes in Germany, an article "
of fuel composed-of brown coal, peat and the dust and waSte
from coal mines, has developed to such important proportions ih
recent years as to attract wide attention, especially at this time.
This kind of briquette forms the principal domestic fuel in Berlin
and other cities in Germany, and is used also in locomotives and
manufacturing industries. It is clean and convenient to handle,
lights quickly and burns with a clear, intense flame, and the com¬
bustion is practically smokeless. Hence, Berlin, though a busy
manufacturing city, is one of the cleanest cities in Europe, so far
as.smoke is concerned. Like m.ost other important German Im-
dustries, this is controlled by a syndicate which includes thirty-
one firms and companies, or more than nine-tenths of all the
producers in the country, and _which jegulates the output and
prices. Tet the prices remain comparatively low. and are com- ^M
mensurate with the means of the poorer classes. Of the l,5f!6,3S5 ^|
tons sold by the syndicate last year, 749.20S. tons were, takenHay
the German railways. 124.3S0 tons were sold to retailers, 497.136
tons were sold to factories and works of various kinds, and 149,-
089 tons, or D.S per cent, were used by German merchant- -^ '
steamers.                                                                                              ;
---------_,-----------   .

Cost Per Barrel of Cement.

The following shows in tabular form a fair estimate of cost of
manufacture per barrel of finished cement for a thousand-barrel'-
per-day plant and also a five hundred barrel-per-day plant, as
given In the prospectus of a new Canadian cement manufactur¬
ing company;

Barrels per day.                                            Barrels per day. ■
Items.            ,--------'-'^--------1               Items.            i---------■--------,

i.ooo.    rm.                                         1.000.    noo.

Marl  delivered.....    .$(1.05      $0,07           Sundry   ...........    JO.IO      $0.12

Clay delivered.....01          .02                                                     ------^     ---------

Common   labor   ...       .03          .07                Total   mfg.   cost   50.-1S      ?0.61'

Chemist,     foreman                                        Supt. and sales..,.        .11)          .20.

and  sliilled labor.        ,03          .07           10%  int.   on  plant.        .10          .15

Repairs    ...........07          .10                                                     --------     ---------■

Fuel,  total........!2          ,12                        Grand total .   50.73      $0.96

Pacldng   ...........03          .04

,    The  above   estimates  have  been  proved   In  the light  of ex¬
perience to be such as can be realized in practical work.

They include interest on investment for works and also repairs.
These items make all earnings above this amount In the nature
of double dividnds.                               ;..   ,

Steel, Cement and Corrosion.

Prof. Samuel B. Newberry comes to the help of steel structures
and by an appeal to eher. Istry, proves, to the satisfaction of
these «ho wish it to be so, that to inclose our steel structures
in Portland cement, carbonic add gas cannot gain access
tf the steel, anu even if of sufficient porosity for air to pass
through, the carbonic acid Is extracted from the air by the
cmtnt. ■ To prove It he cites the story of certain steel pipe at
Grenoble, France, that had been laid in cement for fifteen years,
and cn being taken up for inspection was found to be perfectly
s ivrd.