fluted nails

Masonry nails found in Brooklyn. Age would be a guess--- though probably 1910's-30's, judging from the roughness of the cast and the overall look of them. The earliest reference I could find to fluted nails was the brief mention of an improved variety in the 1858 Annual Report of the Royal Cornwall Polytechnic Society.

The Hecla Iron Works

The Hecla Iron Works, c. 1905

The Hecla Iron Works, co-founded by Niels Poulson and Charles Michael Eger in 1876, was a major player in the construction of 19th century New York City. Their foundries produced everything from simple exterior building ornaments, stair railings, balconies and elevator cars, to
prefabricated building fronts and the 133 original entrance kiosks to the IRT subway system.

Despite the ongoing demolition of historic industrial structures in Williamsburg, the 1897 showroom (the four-story building at right, below) as well as an original foundry building are still intact at N. 11th and Berry Streets.

As an aside, notice the recently completed (1903) Williamsburg Bridge rising in the distance at left in the 1905 illustration.

Advertisement from The Catalog of The Annual Architecture Exhibition, T-Square Club, 1905: