There has been no census since the U. S. census of 1850, except an informal census, made in 1852, for the purpose of dividing the city into wards anew. The estimated population now is about 150 to 175,000 inhabitants--permanent population--including the floating population at this season, it would probably reach not less than 210,000 inhabitants. The U. S. census was taken in the summer months, and is very incorrect as to the absolute population of New Orleans. Very respectfully, Your obed't serv't, J. B. WALTON, _Secretary_. By reference to the abstract of which Mr. Walton speaks, we find that the value of real and personal property is summed up as follows:-- Real Estate, $67,460,115 Slaves, 5,183,580 Capital, 18,544,300 ----------- Total, $91,188,195 CITY HALL, BOSTON,} Dec. 31, 1856. } _Dear Sir_:--Yours of the 25th inst., addressed to the Mayor, has been handed to me for a reply--and I would accordingly state that the value of real and personal estate in this city, on the first day of May, A.D. 1856, was $249,162,500. The census of the city of Boston, on the first day of May, A.D. 1855, was 162,748 persons. The estimated population of the city of Boston at this date--say January 1st, 1857--is 165,000. Yours, very respectfully, SAML. T. MCCLEARY, _City Clerk_. ST. LOUIS, } Feb. 27, 1857.} H. R. HELPER, ESQ., New-York: _Dear Sir_:-- In reply to yours of the 9th inst., I beg leave to state, that a census of our population was taken in the spring of 1856 by the Sheriff, and although it was inaccurate, yet the population as returned by him was then 125,500. That his census is too low there is no doubt. Our population at this time is at least 140,000. Our last assessment was made in February, 1856. Value of real and personal estate, is, in round numbers, $63,000,000. Trusting this information will be sufficient for your purpose, I remain, Yours, &c., JOHN HOW, _Mayor_. MAYOR'S OFFICE. CITY HALL, BROOKLYN,} January 24th, 1857. } H. R. HELPER, ESQ., _Sir_:-- The answers to your inquiries are as follows: The last assessment of property in this city was made in August, 1856. The value of all the real and personal property in the city, according to that assessment, is $95,800,440. A census of the city was taken in 1855, and the number of inhabitants, according to it, was 205,250. The estimated population now is 225,000.