Daily globe. [volume] (St. Paul, Minn.) 1878-1884, 1883-08-22

reasonable time after the sale. The par
ties may go in company or singly.
Sections Il and Z -ATathemdtics and Is
tronOnsy and Mechanical Science.
The section of Mechanical Science met
yesterday with the Section of Mathematics
The session of section A was opened by
Prof. G. A. Young with remarks on
THE PLANET URANUS.
He said that the result of the past years
observations at Princeton with the great
equatorial had been to indicate a slight
ellipt1ci.y in the planet and also to show
that there existed upon its surface certain
apparent dents or marks, the latter being
perhaps yet to be utilized in ascertaining
the rotary speed of the planeS.
The ellipticity of the body would appear
to indicate high rate of rotation. A
bending of the belt toward the plane of
revolution of the satellite is also observa-
bic. The next subject was on the light
variations of T. Monocerotis" by E. F.
Sawyer, The paper not having arrived it
was read by title only.
ORBIT OF THE GREAT COMET.
Orbit of the great Comet of 1882" was
the subject of the next speaker, Edgar
Frisbie, of Washington, D. G. The orbit
as computed atlWashington was computed
from their observations taken with great
care and precision, though they may not
have been entirely exact owing to the
probability or possibility of mistakes be-
ing made in observing the nucleus which
appeared to shift. The orbit as calculated
however, corresponded very closely with
the best observations taken elsewhere.
The track of the comet was almost entire
ly IN the southern hemisphere, its time
beneath the plane of the elleptic being
793 years and above the plane two and
half hours. The paper was extremely in
teresting but far above the comprehension
of the ordinary reader, technical terms
Astounding which none could understand
outside the astronomical student.
SURFACES OF THE SECOND DEGREE.
"Descriptive geometrical treatment of
surfaces of the second degree" was the IT,
tie of the next topic presented by J. Bur-
kett Webb. The subject was illustrated
by geometric figures drawn on the black
board and was so techinal and
abstruse as to prevent a reproduction.
LONG PLANE SURFACES
w. A. Rogers next gave a method of
testing longsplane surfaces, applicable to
tho alignment of planer-beds, lathe beds,
heavy shafting, etc. He spoke only ten
minutes and was listened to with close at
tention but it would require SCIENTIST to
give readable synopsis of the learned
talk.
ROTATION OF DoMEs.
"The Rotation of Domes" was the next
topic by G. W. Hough. The history of
all domes in the United States is that they
are difficult to operate when they get old.
The dome of the observatory of Chicago
is of a cylindrical form and very high
Domes are liable to get out of order
through the settling of wall, and it some
times becomes almost impossible to move
| them on account of their great weight.
The president, A. M, Young, said gas en-
gines are used in moving domes but he
thought steam engines better for the pur-
pose. The next papers, ''The Commercial
and Dynamic Efficiency of the Steam
Engine" and centrifugal Action in
Turbines" were read by title.
| TERRA GOTTA LUMBER.
| Z. R. Baker next read an interesting pa
per on SEA Comparison of Terra Gotta
Lumber with Some Other Building Mate.
rials.' The terra Gotta lumber is composed
of refuse potters' clay and sawdust mixed
Its breaking weight and resistance are
good. Its permeability to air is found by
careful experiment to be eighty times a:
great as that of pine and 135 times that OF
| hri0E TIC hold lie ie
one-half that of pine and its heat con
ducticity not nearly the same as brick. Il
is very porous material, and in santa
ry point of view is therefore preferable to
less porous materials for walls, for it per.
mits better circulation of air, holds less
moisture and carries off less heat. It i:
therefore believed to be a better
building material than brick. By expert
ment it was found that the average time
required for the comparison volume of all
to pass through pine was 1,161 seconds
and to pass through brick $50 seconds
lumber only one and one-third seconds
were required. Although terra Gotta lum.
Der has been considerably advertised and
is produced in considerable quantities al
Perth Amboy, New Jersey, yet there is
0OUOOAOOo AAOeAO hAOWh VI IL U0I0 Wu6T6
lumber is so abundant. The refuse pot.
ter's clay is found abundantly in New
Jersey and elsewhere. 1t is prepared by
thoroughly mixing the sawdust with the
clay and then burning out the sawdust
Each particle of the sawdust leave:
cavity and the cavitie;
thus formed render the material quite
porous, The lumber is cut with saws anG
may be worked with ordinary tools.
DESCRIPTIVE GEOMETRY.
G. NJ. Woodward gave the next paper OF
descriptive geometry and used algebrait
formulas in connection with geometry il
his blackboard illustrations.
The same gentleman also spoke for five
minutes on the velocity of the piston of
crank engine, demonstrating his ability
as frst-class mathematician. He was
followed by j. B. Webb, who spoke for five
minutes on Improvements in shaping ma
chimes. He drew the best form of ma
chine and suggested new method Of
doing away with the variable spring in the
tool end of the ram at different points in
its motion. This is effected by fxing.the
ram upon the bearings and thus causing
them to do the moving and securing q
constant distance from the fulcrums in
the different points of the ram, The fol.