The Sam Houston Zephyr was one of two regional streamliners offering express passenger service between Dallas and Houston, the other being the Southern Pacific's Sunbeam. It originally operated with one of the shovel-nose articulated trainsets built for the Twin Zephyrs of 1935. That original trainset was destroyed by fire in 1944 while Rock Island (which jointly owned the Fort Worth-Houston line and switched off  its management every five years) was in charge of the line, whereupon Rock Island and Burlington introduced "new" (or, at least, new to this route) equipment to cover the duties of the Sam Houston Zephyr and to supplant the former Texas Rocket with the new Twin Star Rocket (see that page for more details). 

While the Rock Island (or the typesetter at the publisher) may have neglected to insert the star denoting that the dining car for the Sam Houston Zephyr was air-conditioned, it most certainly was. The car survives today, in the collection of the Galveston Railroad Museum...the Budd-built Silver Hours Parlor-Diner-Observation. It originally featured 22 individual armchair seats in its first-class observation-parlor section, and 24 seats at 6 tables for four in the dining section (which was open to both coach and first class passengers, as was generally true for most American passenger trains). Both sections featured air-conditioning...with the notable exception of the kitchen. There is a ventilator in the kitchen area which scoops air from outside as the train moves, but as far as cooling or ventilation is concerned, that's it. And if you take a close look at the range in the back corner, you will discern that it is a charcoal- and wood-burning stove...still in common use by professionals in the era when the car was built (1939). So, imagine cooking over a charcoal- and wood-burning stove...without air conditioning...in the middle of summer...between Dallas and Houston. It WAS a tough job....