I stumbled on the double roasting pan and thought, hmm, that's different. A roasting pan with a rack inside, I've seen, even purchased one for my hope chest before I got married. But the first tidbit I'm sharing came with a picture and it does look different. I did search google images for a photograph of one but couldn't find any. However, I do believe that my character in my latest novel The Innkeeper's Wife would have used one.
Double Roasting Pan —
One of the requisites to the success of a kitchener is a double roasting pan. When meat is put in a common pan in a hot roaster, the heat more or less dries up and burns the fat and gravy upon the pan, and so creates a very objectionable odour, which settles upon the meat, making it taste, as is familiarly said, "oveny." The true remedy is the provision of a double roasting pan. It consists of one pan within another, so as to leave a space between them sufficient to hold from one to three quarts of water, according to size. The corner of the inner pan is cut off, to allow of the water being poured in. The space allowed for the water being nearly filled, the fat and gravy that drops upon the inner pan will not dry up or burn, consequently the objectionable odour does not arise; the meat is therefore as sweet as when cooked before the fire, and the gravy and dripping, not being liable to receive the ashes and cinders inseparable from an open fire, is of the best possible quality, the dripping being distinguished by a degree of purity and whiteness unattainable by any other process.
Here's a recipe that mentions using a double roasting pan
Take 1 forequarter of spring lamb, broil till light brown color; lay in a double roasting pan, or dripping pan with another covering it closely as may be made to fit. Have a mixture of vinegar, salt, pepper and butter, add boiling water and baste the lamb as often as required to keep from being dry. Roast till well cooked. Mrs. Rufus Waples.
Another comment about using the double roasting pan
There has recently come into use a double-iron pan for roasting, which has a great many good qualities, and settles satisfactorily the question and use of covering meats while roasting. If used, follow very carefully the directions given with it, that the roast may be neither too flabby and steamed, nor too dried up. The old-fashioned Dutch oven is, of course, the best of all; the patent roaster, with its clockwork to make the roast revolve, is also admirable; unfortunately they are fast disappearing. The time allowed for these is slightly more than for the oven, but not more than 1 or 2 extra minutes to the pound.