The subscriber, as Secretary of the Corporation of the New York Chamber of Commerce (instituted 5th April, 1768), in reviewing the minutes of that respectable Association, found the following astronomical observations for determining the Latitude of the City of New York made in October, 1769, by Mr. David Rittenhouse of Philadelphia, and Captain John Montresor of the British Corps of Engineers, at that period stationed in this City. These observations, it is presumed, have never been published, and may be considered of sufficient importance to be preserved in the archives of the New York Historical Society. JOHN PINTARD. The accompanying extracts from the minutes of the Chamber of Commerce were as follows: NEW YORK CHAMBER OF COMMERCE, _7th November, 1769_. At the desire of several members of the Chamber, they had requested the President to apply to Messrs. David Rittenhouse and John Montresor to take the Latitude of the Flag Bastion on Fort George in the City of New York. NEW YORK, _October 12th, 1769_. At your request, in behalf of the Chamber of Commerce of the City of New York, I have made the following observations with the Pennsylvania sector of six feet radius on the Southwest Bastion in this city. Zenith distance on the Meridian of Capella ° ′ ″ Octr. 9th, morn 5 2 0½ 10th, do 5 1 59 of Castor ° ′ ″ 10th, morn 8 19 51 12th, do 8 19 51 Having carefully computed the Declinations of the above stars from their latitudes as settled by Dr. Bradley, reduced to the present time and corrected by the observation of light and variable motion of the earth’s axis, I find, the Latitude of the place from the observations of Capella to be 40° 42′ 9″ and from those of Castor 40° 42′ 7″, a mean whereof is the Latitude of the Fort, 40° 42′ 8″. I am sir, your very humb. servt. DAVID RITTENHOUSE. to John Cruger President of the Chamber of Commerce Observations made at the Flag Bastion in Fort George in the City of New York, principally with the sector belonging to the Province of Pennsylvania, of six feet radius, by Messrs. David Rittenhouse and John Montresor, Engineers, October, 1769. Zenith Distance of Capella October 9th 3h 50′ morn 5° 2′ 0½″ 10th 3 46 do 5 1 59