December 24, 2004

Ancient Romans Had Hotels with Central Heating. The ruins of an ancient Roman hotel were recent discovered underneath a German bus terminal. I found it fascinating that they had central heating:

After the big nosh, travelers would have had the option of staying for the night at the hotel, which was made of slate and bricked with narrow joints.

The foundation was raised to allow for a wood-fueled furnace at the bottom of the structure. Hot air from the fire would have risen naturally to fill chimneys located within the guest rooms. The hot air also warmed the walls, which were made of partially hollowed-out bricks.

Sauer said the complex was energy efficient, since the forests around Neuss already had been mostly depleted before the inn’s heyday. In addition to the underground heating system, a slate roof on the building captured the sun’s heat, somewhat comparable to how solar panels operate today.

Martin Haidinger, a Vienna University historian who has worked on similar projects in central Europe commented, “This gives us a fascinating insight into another chapter of Roman life, and confirms that some aspects of society were remarkably similar to our own.”

(via GeekPress. )

Want to Know the Biggest Size Photos You Can Print with That New Digital Camera?

Here’s how to find out:

Want to know how big a print you can make before you start to lose sharpness compared to film? It’s simple and here’s the formula for general cases:

Long print dimension in inches = 4 x (square root of megapixels)

For example, for a four megapixel camera the square root of four is two. Two times four is eight. Thus the biggest print you can make without losing sharpness compared to film at normal viewing distances is is 6×8.” From a sixteen MP camera likewise you could go 12×16.” Of course you can print bigger, just you won’t have the sharpness of film. Also few people are able to get all the sharpness of which film is capable, making this harder to compare.

... Don’t worry too much about this, since sharpness is not as important in color as it is in B/W. I make 12×18” color prints all the time from 3 to 6 MP cameras and they look great, since I only print images that are good to begin with.

So, here’s a helpful table.