Bill GottesmanPrecision Sundials LLC

Renaissance Focusing Sundial

A “Watch” accurate dial using Focused Light

Notable Features

• Modified Equatorial Dial• Scale is Expanded• Uses Focused Light• Adjustable for Latitude, Eot,

and Daylight Savings• Software assists alignment• C. M. Lowne in BSS Bulletin

98.1 independently reported similar idea for focusing sundial.

• US Patent 6,301,793

Modified Equatorial Dial

•Equatorial Circle is expanded into a helix to increase its rigidity.

•Readable on Equinoxes

•Helix connotes the passage of time

Scale is Expanded

Eccentric Equatorial Pipe Dialby Kate Pond

Mirror is 6 minutes wide, but image is focused to 2 minutes across, the same as the sun in the sky

Focused image is crisp.

Cylindrically ground mirrors keep the image in focus at all times

Mirrors and Mount

Mounted Mirror

Set Screw Holes

Single Beam Movie

Adjustable for Eot, DST

Adjustable wedges allow sturdy and accurate setting of latitude

Wedge Graphic

Wedges set for 46 degrees

Software Assists Alignment

Alignment Answer

New Developments• Focused beam is 2 minutes of time wide. Can this be made

narrower to allow a more precise reading?• Not with the beam itself, but…

• By casting two beams adjacent to each other, the space between them can act as a cursor, and be made as narrow as one desires, even to just a few seconds of time.

Two Mirrors Create Two Focused Images

Two Mirrors

Two Beam Movie

Smithy Granite Machine

End

Sawyer Equant Schmoyer Sunquest

Mirror Demon-stration

Like a concave spoon, image inverts when moved away from

mirror.