Dear Sir,--I at length find myself, though not quite well, yet sufficiently so to resume business in a moderate degree. I have, therefore, to answer your two favors of April 23 and May 3, and in the first place to thank you for your attention to the Paccan, Gloucester and European walnuts, which will be great acquisitions at Monticello. I will still ask your attention to Mr. Foster's boring machines, lest he should go away suddenly, and the opportunity of getting it be lost. I enquired of Mr. Hamilton the quantity of coal imported; but he tells me there are not returns as yet sufficient to ascertain it; but as soon as there shall be I shall be informed. I am told there is a considerable prejudice against our coal in these Northern States. I do not know whence it proceeds; perhaps from the want of attention to the different species, and an ignorant application of them to cross purposes. I have not begun my meteorological diary, because I have not yet removed to the house I have taken. I remove to-morrow; but as far as I can judge from its aspects, there will not be one position to be had for the thermometer free from the influence of the sun both morning and evening. However, as I go into it only till I can get a better, I shall hope ere long to find a less objectionable situation. You know that during my short stay at Monticello I kept a diary of the weather. Mr. Madison has just received one comprehending the same period, kept at his father's at Orange. The hours of observation were the same, and he has the fullest confidence in the accuracy of the observer. All the morning observations in Orange are lower than those of Monticello, from one to, I believe, fifteen or sixteen degrees; the afternoon observations are near as much higher as those of Monticello. Nor will the variations permit us to ascribe them to any supposed irregularities in either tube; because, in that case, at the same point the variation would always be the same, which it is not. You have often been sensible that in the afternoon, or rather evening, the air has become warmer in ascending the mountain. The same is true in the morning. This might account for a higher station of the mercury in the morning observations at Monticello. Again, when the air is equally dry in the lower and higher situations, which may be supposed the case in the warmest part of the day, the mercury should be lower on the latter, because, all other circumstances the same, the nearer the common surface the warmer the air. So that on a mountain it ought really to be warmer in the morning and cooler in the heat of the day than on the common plain, but not in so great a degree as these observations indicate. As soon as I am well enough I intend to examine them more accurately. Your resolution to apply to the study of the law, is wise in my opinion, and at the same time to mix with it a good degree of attention to the farm. The one will relieve the other. The