Washington architects Joseph Hornblower and James P. Marshall were brought in to oversee many of the structural changes to the room. A pair of iron columns that supported the floor above were replaced by a single iron beam spanning the width of the room imbedded into the outer load bearing masonry walls. The beam was encased by plaster on lath as was the drop ceiling, which would serve as a canvas for the decorative painting by the designer Grace Lincoln Temple. The tall, narrow windows were enlarged and the doorway was altered to allow more light into the room.
In the center of the room was a huge aquarium designed by Hornblower and Marshall that contained a special fountain and brightly-colored fish, plants, and stones. It rested on a massive table also designed by the architects (fig. 1). The colorful fish inside were just a few of the live specimens on view in the room meant to encourage children to marvel at nature's beauty. A shiny white mosaic floor with colorful borders of red, blue, green, yellow, and black tiles inspired by Celtic designs was installed in the room (fig. 2). The firm designed many of the room's furnishings as well.
In order to ensure the most enjoyable and stimulating experience possible, Langley directed Hornblower and Marshall to design new display cases that were low to the ground, closer to the child's height, so that the specimens inside could be more easily viewed. Constructed of light maple wood, the cases easily harmonized with the bright interior. The numbers of specimens in these cases were kept low so as not to overwhelm children.
A pair of leafy wrought iron gates designed by the architects were attached to new wood framed glass doors (fig. 3). The foliated design alluded to the natural world on the other side of the glass doors, making the doors less a barrier to the outside than a transition. It were as if nature, in the form of climbing intertwined ivy, had permeated the room in a tangible way.