Evening star. [volume] (Washington, D.C.) 1854-1972, 1902-11-01

these problems get into my head they
seem to stay there In all their minute de-
| In such manner 1 produced the COPY for
both nv books. As the point system of
| writing Is based punctures in paper
| mace py a stylus, and are similar to holes
MADE by pin point In paper YOU can
readily see how long 1 was about the task
especially when YOU bear in mind that I
naa to create In this writing all the many
different characters used In the Variations.
The Slate for the Blind Used.
'Of course. after I had written down the
problems some one had to transcribe them
In ordinary writing My brother Addison
wrote the first book for ne. my wife has
just finished this task with the second
When the proofs OF my first book came
Addison read them to me and made the
corrections that 1 ordered Only half
dozen mistakes have been found in the book
In all these years. and these are misspeIIed
words
In addition to my memory I have had
| recourse to the slate for the blind
Ihis slate Is a square board cut IN into
Httie sunken squares, and into which are
placed type-like affairs that represent certain
nsures For instance. the numerals are
made almost wholly by the use of the let
tiers and V. In its proper position. T rem
Fesents the numeral one Turned on its
side and with the cross line to the left II
Is TWO. With the cross line down It is
three, and with the cross line to the right
1t Is four. in its natural position is Ave:
with the opening to the left It is six; with
the opening down. seven: and with the
opening TO the right. eight. represents
nine, ana plank type naught. There are
also characters for simple algebra but none
higher. Therefore. l have had to deveIon
a system OF my own. using the regular and
Few types employed by the blind, for i
could get no one to cast me the various
queer characters that 1 needed. This sys-
Ten Is often complex owing to the fact
ohat nave had to employ all the myriad
enaracters known to algebra geometry.
,rlsonometry and calculus, which last
oranch includes Greek alphabettca char
a as Here again in my work memory
pays a large part for 1t would never do to
Iorget the scores OF names 1 have given the
ordinary types and the uses to which I
have put them
This is an example Of how use INV
slate. I take a common algebraic cbarac.
Ter and by turning It, as T and Y are
turned TO secure the numerals I obtain
o ons eisnt trisonometrical functions. sine.
cosine. versed sine, co-versed sine tangent.
co-tangent, secant and co-secant.
is only on rare occasions. however.
that use the slate. 1 much prefer to
have to sit down when I work with the
slate" wan '"'
Can't Add Mentally.
Here Mr.. CARL raised a warning hand
But don't envy me nv memory" he
said, laughingly. II fear that. for many
ordinary uses. 1t isn't much good Why.
90 you know that it's a fact that I cannot
DO simple problems in addition, subtra ction.
multiplication and division in my head7
When want to figure up my living ex-
Penses; Tor instance, / am compelled to
seek aid of my slate. Strange. isn't 1t?
Neither am I a lightning calculator az
NAUTICAL reputation. 1 work with painstak-
ing sioWness from sheer inability to CRASH
thinss mathematical quickly. I do believe
Inat my brain, when II Is wrestling with
hgures, moves as slowly as that of a boy
Just beginning to learn the significance OF
the multiplication tables"
MI Carl is going to call his new book
Afterthoughts on Calculus Of varia-
tons. These "Afterthoughts" deal with
the most formidable problems known in
mathematics. which also have a formi-
lens. Robbed of technical language they
are problems that have to do with equal
pertmeters. but what they have to do with
equal perimeters deponent knoweth not,
though he listened attentively to detailed
and simpliied explanation by Mr.. CARL
Although Mr.. CARL gained immediate
Tame after his first book appeared. he is
known personally to very few Of the math-
ematicians. The absence of sight has kept
him from attending the gatherings of the
learned men of figures but 1t has not pre-
ars by mall. Prof Simon Newcomb, the
famous scientist and astronomer, Is repre-
sentative of the men who have sat at Mr.
CarlTs feet.
Lecture to Columbia Professors.
Mr.. CARL Is fellow at Columbia Univer-
sty. His friend, Mayor Low, with whom
during college days he was wont to soJourn
at Fritz's, a one-time famous resort for
Columbia students. secured Mr.. CARL the
fellowship In recognition of his work. Every
year he delivers a course Of lectures at the
university to the mathematical professors,
among whom are such leaders in the edu-
cational world as Dr. Thomas Fisk and
Prof. ]. H. Van Amringe. head Of the math-
ematical department. The late Prof Will
liam G. Peck of Columbia, who made a big
name In the college world by compiling
that stupendous mathematical work, "Da-
vies' Legendre," often consulted Mr.. CARL.
Mr.. CARL Is slight In stature and build,
well groomed and remarkably free Of the
nervousness usually exhibited by close stu
dents. When he stated that he was in his
sixtieth year he added, Their pathetically:
Looking back over these years my one
regret is. not so much that I am blind as
that I've forgotten nearly all ever knew
of my Latin and Creek