✔ 100% Money-Back Guarantee on Eligible Items
✔ Prices Displayed in Your Local Currency
✔ Final Price = No Surprise Import Fees
✔ Complimentary Insured Worldwide Shipping on Qualifying Orders
✔ Select Collector & Specialty Pieces May Require Secured Delivery Handling
by Theodore Gray (Author)
The international bestselling author of How Things Work and The Elements Trilogy turns his focus to a visual exploration of the inner workings and functionality of the marvelous machines that run our world--from the first steam engines to giant turbines to today's tiny electrical engines.
In Engines, the always entertaining and informative Theodore Gray explores the glorious guts and intricate innards of dozens of impressive machines. Through his engaging and unexpected stories and Nick Mann's trademark gorgeous photography, Gray takes us on a journey from ancient Greek steam engines to our most sophisticated twenty-first-century machinery. We take time to appreciate the detailed functionality of the internal combustion engine, the connection between magnetism and electric motors, as well as hydraulics, robotics, and more. Each chapter builds on the previous, illuminating the evolution of engines and revealing the ingenuity brought to bear as humans invented and perfected these marvelous mechanical systems. Along the way, Gray regales us with tales of his own experiences working with and collecting these machines. For fans of how things are made and how they work, Engines is a loving tribute to the mechanical world.Author Biography
Theodore Gray is the author of How Things Work, The Elements, Molecules, and Reactions, as well as Theodore Gray's Completely Mad Science. He is the creator of the bestselling iPad apps "Elements" and "Molecules," which have both been named App of the Week by Apple, and he was the director of "Disney Animated" (also honored by Apple as iPad App of the Year). Gray appeared onstage with Steve Jobs several times in his capacity as a software creator. He also co-founded Wolfram Research, Inc., makers of the widely used software Mathematica and the Wolfram Alpha website. He lives in Urbana, Illinois.
Nick Mann is a photographer specializing in taking beautiful photos of inanimate objects on black backgrounds. His other work includes The Elements, Molecules, Reactions, and How Things Work. In his other life he designs and makes specialized note- taking fieldwork equipment, as well as working in the quality control department for a large automotive company. He lives with his wife and stepson in Urbana, Illinois.- ✔ Authenticity Guaranteed — Verified Designer Goods
- ✔ Sourced from Authorized European/U.S. Luxury Distributors
- ✔ Secure Checkout — SSL Encrypted Payments
- ✔ Fast Global Delivery — 3–11 Business Days
- ✔ Easy Returns on Eligible Items
- ✔ 100% Money-Back Guarantee — Full Refund if Not Satisfied
AUTHENTICITY GUARANTEED
Reserved for you — complete your purchase to secure this piece.
OFFICIALLY AUTHORIZED RESELLER
Discover Officially Authorized Authentic Items at STORE7994.com - Certificates Available on Request!
Independently verified for store quality and customer safety.
Trust score: 91/100
All designer items offered by STORE 7994 are sourced from trusted luxury distributors and verified through independent authentication services.
Learn how STORE 7994 authenticates luxury items
Guaranteed Authentic — Includes Brand Documentation & Third-Party Verification Options.
Shipping information
- Free Shipping* on all orders over $300 USD to most countries* Estimated delivery: 2-5 business days Mon-Sat to U.S., CA, EU etc.
- Tracking available: DHL Express
- Store 7994 Shipping policy
- Global delivery in 3–9 business days (location dependent).
- Free Worldwide Shipping $300+. International duties & VAT are calculated by destination country and may be collected upon delivery. UK orders are subject to 20% import VAT upon delivery.

Our innovation isn’t just in the brands we carry — it’s in the way we connect them. From our automation engine that keeps collections globally updated to our commitment to authenticity-first presentation, STORE 7994 exists where timeless design meets modern precision.
Every product we offer is:
Elevated · Intentional · Exclusive · Authentic
STORE 7994 is an authorized reseller of luxury fashion houses. Certificates and proof of authenticity are available to brand owners and partners upon request.
Returns & Refunds
We want you to shop with confidence at STORE 7994. If your purchase does not meet expectations, eligible items may be returned under the conditions below.
Return Eligibility
Items must be unused, unworn, and in original condition with all tags, packaging, and accessories included. Items showing any signs of wear or damage will not be accepted.
Return Window
Return requests must be made within 14 days of delivery.
Return Shipping
Customers are responsible for return shipping costs unless the item is defective, damaged, or incorrect.
Luxury Items
Items valued over $1,000 may be subject to a 7% restocking fee upon approved return.
Non-Returnable Items
For hygiene and product integrity reasons, the following items are final sale once opened or used:
• Underwear
• Fragrances
• Any worn or used items
Made-to-Order Items
Custom-designed products, including STORE 7994 hoodies, are made exclusively for each customer and are final sale. These items are not eligible for return or exchange unless defective or incorrect.
If you receive a defective or incorrect item, please contact us and we will make it right.
International Shipping & Duties
Many of our products ship directly from trusted international partners. Any applicable customs duties or import taxes are calculated at checkout and are non-refundable, even if the item is returned.
Returns & Associated Fees
All approved returns are subject to a $24 return processing fee. For international orders, duties, taxes, and return fees will be deducted from the original payment.
Shipping Policy
Complimentary shipping is offered on orders over $300. Orders below this threshold are subject to standard shipping rates at checkout.
>