Dunbar's idea of the relation the government should sustain to scientific research is still further set forth in his last letter that has been preserved in the Jefferson manuscripts. From this letter, which bears the date of December 17, 1805, the following extract is taken: "I have just received from London a six feet Gregorian reflecting Telescope with six magnifying powers from 110 to 550 times; hitherto from a liberal construction of the act of Congress, by the Collectors of the Mississippi Territory residing at Fort Adams, I have been in the habit of receiving books and instruments free of duty, but Mr. Browne at New Orleans is so rigidly faithful as a public servant that he admits of no exemptions neither in favor of the Mississippi Society, for which I have lately imported a chest of books; nor in favor of this valuable instrument, the cost of which in London was about 150 guineas, [about $750]. I suppose Mr. Browne is quite correct as to the letter of the law.... I have just sent off an order for Mr. Briggs, Mr. Dinsmore and myself, for astronomical instruments & chronometers to the amount of 300 guineas [about $1,500], all of which as well as that just received, will in some shape be applied to public use and benefit & might therefore be entitled to a claim upon public indulgence."[60] The significance of this extract is twofold. It shows that Dunbar devoted his time to scientific investigation not only to gratify himself but to serve the public. His love of science for its own sake made "favorite amusements" of labors that would otherwise have been very onerous. His desire to benefit others through these investigations led him to fulfill that true test of all greatness,--service to one's fellow-man. This extract shows further the contagion of an enthusiastic devotion to a great cause. Dunbar and his friends, remote from the intellectual centers of the world, constituted themselves into a society, which spent a larger sum of money for scientific purposes than perhaps any other private scientific organization in the history of the State. He sought the co-operation of all thinking men with whom he came in contact. He was active in his efforts to collect all facts of scientific interest throughout his part of the country. That he was often disappointed in these efforts, is shown by more than one passage in his writings. In his "Description of the Mississippi and its Delta" he expresses his regret over "the extreme inattention of persons, even of some education, to the most curious phenomena passing daily under their review."