52 



THE GUIDE TO NATURE. 



be secured, it would be well to take ad- 

 vantage of this opportunity to see these 

 and other rare things seldom seen even 

 in museums. 



Tubular Concretions of Iron. 



BY HOWARD R. GOODWIN, PHILADELPHIA, 

 PENNSYLVANIA. 



On the west bank of the Pensauken 

 Creek, near North Pennsville, New- 

 Jersey, is a large hill of sand which 

 contains considerable iron ore of the 

 variety known as limonite. This ore 

 has formed a conglomerate of small 

 pebbles and sand which takes some 

 curious forms. 



Part of the formation consists of 

 sheets or strata more or less con- 

 torted, and part of tubes or pipes of 

 various length and thickness. 



The specimens illustrated average 

 seven inches in length by three inches 

 in diameter, the double tubes being of 

 common occurrence. Some of the tubes 

 taken out at the time of my visit to the 

 locality were over three feet long and 

 full}' ten inches in diameter, with 

 walls one inch in thickness. 



After getting out the tubes, the 

 sand in the interior, which is much 

 lighter in color than the material sur- 

 rounding them, is easily removed with 

 a sharpened stick. 



The curious specimens are rust 

 brown in color and make an inter- 

 esting, if not beautiful, addition to 

 the cabinet. 



In Clinton Township, Vinton 



County, Ohio, is a sandstone that con- 

 tains spherical concretions which, re- 

 leased by the decomposition of the 

 sandstone, roll down to the foot of the 

 hill where they resemble a lot of rusty 

 cannon balls. 



Limonite, or brown hematite, is an 

 abundant ore in the United States and 

 contains, when pure, about two thirds 

 its weight of iron. 



The varieties known as brown and 

 yellow ochre are common materials 

 for paint wdiile bog ore, an earthy 

 variety usually containing considerable 

 phosphorus derived from organic 

 sources, is said to afford a good iron 

 for castings. 



Gothite, turgite and melanosiderite 

 are other varieties recognised by min- 

 eralogists. 



Three Bronx Localities for Stilbite. 



BY EDWIN W. HUMPHREYS. 



A recent examination of the rock 

 in an excavation back of the Museum 

 Building in the Botanical Gardens, 

 Bronx Park, New York City, revealed 

 some good specimens of straw-colored, 

 though in parts it was white or nearly 

 white, stilbite. The crystals occur in 

 more or less perfect sheaf-like aggre- 

 gations. The mineral is somewhat 

 weathered and crumbles easily. 



The finding of stilbite here recalled 

 to mind two other localities in the 

 Borough of the Bronx at which stil- 

 bite has been found. They are Third 

 Ave., near 179th St., and Bryant Ave., 

 near 170th St. At the former place, 

 the stilbite was similar in color and 

 form to that found in Bronx Park. 

 In some parts it was coated with iron. 

 Some of it, moreover, was more trans- 

 lucent and of a darker yellow color. 

 This darker stilbite was not arranged 

 in sheaf-like groups, the crystals, 

 though crowded together, rose from 

 the enclosing rock as individuals. At 

 the Bryant Ave. locality the stilbite 

 was of a reddish brown color and oc- 

 curred in flat rosettes. It must have 

 been very abundant here, for a teams- 

 ter said that he had carted away and 

 dumped loads of that "stuff." At all 

 three localities the rock in which it 

 was found was the schist. 



