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FRED MEDART MANUFACTURING CO.

STEEL LOCKERS — STEEL SHELVING — STEEL WARDROBES
GYMNASIUM APPARATUS — PLAYGROUND APPARATUS
GYM SEATS — SWIMMING POOL EQUIPMENT
CHICAGO OFFICE

NEW YORK OFFICE
16 WEST 61st STREET METAL SPECIALTIES 326 W. MADISON ST.

GENERAL OFFICE AND FACTORY
POTOMAC AND DE KALB STREETS

ST. LouIs, Mo.
April 8, 1939

Dr. Forrest C. Allen
University of Kansas
Lawrence, Kansas

Dear Dr. Allen: :
On the enclosed blueprint we have shown a conventional flat type backboard on
which we have drafted your shooting diagram. The dotted lines represent the
changes in the corresponding zone boundary lines when the diagram is trans-
ferred to the convex faced backboard. When viewed from the front the slanting
lines, which extend towards the upper corners of the convex backboard, will
appear slightly curved. You will note that on these slanting zones we have
shown an auxiliary dotted line 8-1/" from the edge of the board - this line
represents the difference between a carom shot striking the flat backboard on
its extreme edge and the same angle shot striking the convex backboard. We
have taken the liberty to also show, in dot-dash lines, the outline of the
newly designed bank, as suggested by Mr. Porter.

The method used in obtaining the new boundary lines was to compute the angle
of incidence and reflection of your shooting diagram zone boundary lines on
the flat type backboard, using the center of the basket as a focal point. By
applying these same angles to the curved backboard we computed the correspond-
ing lengths of arcs. We are enclosing copies of our computations for your
comments as to whether we correctly interpreted the line of thought you ex-
pressed in your letter to Mr. Weinzettel.

Sheet #1 shows the angles of incidence and reflection of your shooting diagram
boundary lines.

Sheet #2 shows the same angles applied to the curved backboard.
Sheet #3 shows the resultant change in the floor zone boundary lines.

You will note from sheet #3 that the floor shooting zone boundary lines will
spread radially from the face of the backboard towards the end zone on either
side, resulting in a somewhat wider shooting zone for the corresponding zone
on the backboard.

If, in your opinion, the dimensions as shown on the enclosed print are correct,
upon your advice we would gladly paint the diagram on all three or any one of
the sample banks which we are sending you.