The Theory of Sundials
SKU: 1671456744

The Theory of Sundials

Sale price$41.87 Regular price$46.52
Save 10%

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Jul 8 - Jul 13

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

Description

The Theory of SundialsThis is the 7th book in Fred Sawyers Sciatherics series. It is a translation of Joseph Dreckers 1925 classic Die Theorie der Sonnenuhren. This book is not a general introduction to modern gnomonics. Rather, it is the culmination of centuries of research primarily on those ancient sundials that attributed 12 (variable length seasonal) hours of sunlight to each day of the year. The system of seasonal hours was in use for well over 1,000 years and yet in

This is the 7th book in Fred SawyerÕs Sciatherics series.

It is a translation of Joseph DreckerÕs 1925 classic Die Theorie der Sonnenuhren.
This book is not a general introduction to modern gnomonics. Rather, it is the
culmination of centuries of research primarily on those ancient sundials that
attributed 12 (variable length seasonal) hours of sunlight to each day of the
year. The system of seasonal hours was in use for well over 1,000 years and yet
in that time there was never any clear understanding of the true mathematical
nature of the hour lines or curves.

Additional topics include ancient portable dials, Italian and Babylonian hours,
Planetary hours, equal hour gnomonic sundials, Foster/Lambert dials, and bifilar
sundials.

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 1671456744

Discover Niche Categories That Outsell

Top-Converting Item to Boost Your Average Order

4.9 ★★★★★
Based on 2126 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
R
Verified Purchase
RippedOff
Battle Creek, US
★★★★★ 5
Fits the new iPads. Buttons are easily accessible.
Color: 1-Navy Blue
Fits the new iPad. Buttons are easy to reach, and it protects the screen with a soft fell back. Easy white clean vinyl on the outside. It has open vent spots so your device can cool. Slim and sleek. A great value for the money. Buttons are easily accessible. High-quality.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 21, 2026
G
Verified Purchase
Grinosca Garcia
San Leandro, US
★★★★★ 5
Perfect, it fits like a glove.
Color: 1-Navy Blue
I really liked the sleeve, the navy blue color looks very elegant and the material feels resistant but soft to the touch. What I like the most is that the back is translucent, so you still see the design of the tablet. It works great for watching videos because it stands firm when folding it, and turning off the screen alone when closing it is very practical. Because of the price it has, the quality is excellent.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 26, 2026
D
Verified Purchase
Denny
Dallas, US
★★★★★ 5
Great Protective Case for My Mother’s iPad
Color: 2-Watermelon Red, Color: 2-Watermelon Red
I bought this case along with my mother’s new iPad, and it was the perfect choice. The watermelon red color looks beautiful with the pink iPad and gives it a very clean and stylish look. The case feels sturdy without adding too much weight, which makes it comfortable for her to carry around and use every day. The stand feature works really well for watching videos, reading, and video calls. I also like that the case supports the auto wake and sleep function, which makes the iPad feel even more convenient and easy to use. The cutouts fit perfectly, and Touch ID still works without any issues. The translucent back is a nice touch because it still lets the iPad color show through while keeping it protected from scratches and bumps. Overall, this case exceeded expectations and makes a great addition for anyone wanting both protection and style for their iPad.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 14, 2026
L
Verified Purchase
Leon
Massapequa, US
★★★★★ 4
Good product. What you see is what you get.
Color: 1-Navy Blue
Material feels sturdy and was a perfect fit compatible for my iPad. There's adequate grip and padding for a comfortable yet slim feel. Magnets hold it close and in one position when propping it up for watching landscape videos. Back is translucent as advertised. Solid product, put it on as i opened my new ipad for immediate protection. Perfectly safe blind buy if you're also getting that 'frequently bought together' suggestion from Amazon.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 1, 2026
S
Verified Purchase
Sue Fowler
Port Orchard, US
★★★★★ 5
Nice iPad case. Good price, lots of colors,
Color: Papaya
Nice iPad case. Well made, fits great. Love the color!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 8, 2026

recommand products