This hypothesis is supported by the historical data concerning California manufacturing capabilities during the 1870s. This data indicates that other buildings of equal complexity were being manufactured from redwood during this period. As part of the architectural investigation conducted by Architectural Resources Group in 1998, wood samples were taken from various locations throughout the building, and the majority found were coastal redwood ("Sequoia sempervirens"). The samples that were not redwood came from window sash and areas of the building known to have been repaired previously with Douglas fir. In addition, through visual inspection, it was determined that there was a significant amount of redwood in the building despite the various repair campaigns that occurred throughout the years. No primary document has been uncovered to indicate the architect of the Conservatory of Flowers. It is possible that the plans uncovered at Lick's estate were produced by Lord & Burnham, the major manufacturer of greenhouses at the time. The Conservatory of Flowers bears resemblance to many of Lord & Burnham's other contemporary structures, one of which was purchased by D.O. Mills, a trustee of James Lick, in 1872. Numerous printed articles described the conservatory as "modeled after those in the Kew Gardens, London." The San Francisco Public Library also holds a document entitled "Information about Samuel Charles Bugbee", written by a relative, Arthur S. Bugbee, in 1957. It indicates that the architect, Samual Charles Bugbee, whose works included the homes of Leland Stanford and Charles Crocker and the Mendocino Presbyterian Church, also included the Conservatory of Flowers. Unfortunately, there are no primary source materials that have been uncovered that confirm Bugbee's involvement in the design process. There is direct evidence that the New York firm of Lord & Burnham was contracted by the Park commissioners to construct the Conservatory of Flowers. Although Lord & Burnham supervised construction of the Conservatory of Flowers in Golden Gate Park, no primary evidence has been found to suggest or confirm their involvement in the manufacture of the building. The Conservatory of Flowers was an indirect gift of philanthropist James Lick. There is little surviving evidence that details the construction of the Conservatory of Flowers. Records indicate the construction costs were roughly $30,000. The conservatory has 16,800 window panes. The upper dome of the conservatory weighs 14.5 tonnes. Langley's "San Francisco Directory for the Year Commencing April 1879" discussed the construction of the Conservatory of Flowers:  The whole building required in its construction twenty-six thousand square feet of glass weighing twenty-five tons, and two tones of putty.