The basic building materials available at the end of the 19th century were:

Lumber the wood in our homes came from old growth 100 year old trees these were large trees with close grain because they grew slowly,because of this the lumber cut out could be long and straight and had good grain structure. It was also more resistant to decay where as most lumber now is fast grow having more water than quality fiber. it warps out of shape even before you get it home

Bricks were made from local clay and the process was simpler. it is a lot softer than modern brick. some of the original kilns are still visible from New York avenue on the property of the arboretum.

Mortar was not available. a lime mixture based on calcium compounds was used it was a soft material, it was ideal used with the soft bricks of the time. Because of this when you have old brickwork worked on they should not use modern hard mortar but a historically correct mixture which is softer

Modern mortar has only been in use about 100 years. It was formed by adding silica compounds which tend to be harder along with the calcium compounds.

Iron ore that is mined does not have the properties to make it a good building material it is refined to make other ferrous materials

Castiron was the simplest refined product from iron ore.the basic difference from the basic iron ore is that the carbon content was reduced which gave it better structural qualities.Wood patterns are created by skilled pattern makers the foundry then pores melted castiron into impressions in sand molds from the imprints of these patterns. All the pieces come out the same as the original pattern minus a small shrinkage which occurs when the molten metal cools .foundries still use the same process of wood patterns and sand molds as they did for hundreds of years. Intricate designs can be reproduced in quantity . The main drawback with cast iron is that it has good compressive strength by no tensile strength, it will break before it will bend.

Wrought iron was the basic material used in conjunction with castiron where bending strength was required. The basic iron had most of the carbon, which gives iron its brittleness removed, but the other impurities as silica were left in the product. it now could be formed by hammering to elongate it or “wrought” the hammering into shapes also elongated the silica strands these impurities now helped to make the wroughtiron less susceptible to rust when the iron starts to rust further rust is stopped by the silica fibers. unlike cast iron or steel the hammering creates a grain in the material when you break a piece of wroughtirion it will not be a clean break but you will see jagged edges much as the grain in wood. The wrought iron was used in conjunction with cast iron to make structurally sound units that also had beautiful ornamental qualities. the structural strap joined to the cast stringers become the backbone of castiron porch the handrail pipes were also wrought instead of cast

Steel was not economically produced until the end of the 19th century. It is a purer material with precise amounts of carbon and other materials to give it desired qualities of hardness for tool material or other qualities for general structural use.

One drawback is that because of its purity it is a lot more susceptible to rust. Because if it’s cheapness and it’s ease to work with it supplanted wrought iron which now is no longer made and reduced a lot of the castiron used. The structures built from steel do not have the ornamental qualities of castiron.