Mr. Barry is engaged in some painting for this house & the Capitol, and tells me he can get a crate of window glass here for Monticello; & he thinks it safest that he should cut it here & pack it because it will be so much less liable to break in small plates than great ones. I must therefore get you to cut models of the circular panes in stiff writing paper & inclose them to me by the return of the post, writing on each model how many panes will be wanting of that size & form. I suppose that 2. models will answer for the 4. pediment semicircular windows, and two more for the 5. semicircles of the Greenhouse. for the windows of the Greenhouse it will be sufficient to state in writing the size of the panes, & for the skylight of the dome the diameter of the center pane. however you will be a better judge on inspection of all the sashes how many models may be necessary. as mr Barry cannot work in the house while the family & so much company will be in it, he will not go on to Monticello till late in September. I salute you with my best wishes.