Re: Tiffany Summer & Winter car.

Ken Martin Wrote:
> There is a description and drawing on Page 311 of
> the 1877 Railroad Gazette...

This drawing shows the horizontal air space between the outer siding and roof, and the insulated portion of the walls and roof, complete with the controllable vents on the ends, that are a major element of the Tiffany patent. The end vents are positioned along the edges of the car ends, distributed from top to bottom, to allow air to flow through these spaces. The vents on the DSP&P cars are not at the edges, but instead are distributed across the end of the car, near the middle (these are the smaller vents, not the large one that provides air circulation through the ice box and car interior).

Does anyone have any ideas of how the air from these vents was ducted through the air spaces in the sides and/or roof of the DSP&P cars, or if their purpose was different?