The Ottawa free trader. [volume] (Ottawa, Ill.) 1843-1916, 1846-03-20


his chair, whirled round, rolled up
his wild flashing eyes, and said in
about a minute, ga Then said /,
two persons, A and B., departed
from different places at the same
time, and travelled towards each
other. On meeting it appeared
that A had travelled Is miles more
than b; and that a could have gone
BIS journey in l5l days, but B would
have been twenty eight days in per-
forming AS journey: how far did
each travel? He flew round the
room, round the chairs, writing his
little body as if in agony, ard in
about minute sprung up to me and
said, "A travelled 72 miles and B 81
miles-didn't they? Yes Then
said |, What two numbers are those
whose sum, multiplied by the grea-
ter, is equal to II; and whose diff
ference, multiplied by the less is
equal TO II? lie again shot out
of his chair like an arrow, flew
about the room, his eyes wildly rol-
ling in their sockets, and in about a
minute he said, a and T. Well
said |, the sum Of two numbers IS s,
and the sum of their cubes l53.-
What are the numbers? Said he,
instantly, g and s. Now in regard
to these sums, they are the hardest
in Davies algebra. have had clas-
scs Of one hundred scholars who
have not been able to perform Sc
vcral Of them. But young Stafford,
at one reading comprchended them
at flash, ard returned, almost in
stantIy, corretsanswers.
X
Then took him into the mensur-
alton Of solids. Said |, What is the
entire surface of regular pyramid
whose slant height is II feet, and
the base a pentagon, of which each
side is $50 feet? In about two min
utes, after simplifying around the
room, as his custom is, he replied,
'3554.555S.' How did you do it ?
said |. He answered, Multiply 81. Is
by ., and that product by S.5, and
add this product to the product OBJ
tanned by squaring 33.5, and multi
plying the square by tabular area
taken from the table corresponding
to pentagon,' On looking at this
process, it is strictly scientific.
Add to this the fact that | was ex-
aiming Him on different branches
OF mathematics, requiring the APP
plication of different rules, and that
lie went from one sum to another
with rapidity, performing the work
IN his mind, when asked to, and the
wonder is still greater. Then | de-
sired him to find the surface of
a sphere. Hence, said |, REQUIRED
the area Of the surface of the earth.
ITS diameter being 1921 miles 3? lie
replied as quick as thought, 1917
1924 square miles To do it, he
had to square 1921 and multiply the
product by 3.lll6. Then wished
hun to give me the solidity Of a
sphere therefore, said |, What is
the soIidity Of the earth, the mean
diameter being 1857 miles? He
wrlthed about, flew rapidly about
the room, flashed his eyes, and in
about minute said, '259, 992,792.-
Oo3,' To do this he multiplied the
cube of 79lS.7 by 5236. believe
he used a few figures in doing this
sum; but it was not necessary, as
he performed a much larger one in
his mind as | shall soon show. The
next sum / gave him was this how
many rails will it require to fence
a circular field, so that there shall
be as many acres in the field as
there are rails round 1.-THE fence
being five rails high and the ris ten
feet long, or laying ten feet on the
circumference? 'Op said he, Il guess
| can't do it. o! yes can, said he,
leaplng on the floor, and hurrying
about the room and in about two
minutes after he put lis mind upon
1t, he said, it will take l3G,SlS, 09G
rails The mode Of doing this was
Ingenious, and shows his power of
comprehending not only the nature
OF the sum, but also the mode of pc
forming it. On asking him to ex-
plain how he wrought it, he replied,
IF five rails fence ten feet of the
circumference, one rail will fence
two feet; then | shall have fenced
apiece Of ground tow feet at the
circumference and . at the centre.
But by dividing this in the centre
and reversing the ends, it will be
one foot wide.
now how far must this strip of
land extend to make an acre? Null
tiply 100 by 272s and it will give
the square feet in an acre, which
is 1890. This is the radius of the
circle. Twice this is the diameter,