December 13, 1907] 



SCIENCE 



831 



lithographs, in three colors, of typical locali- 

 ties within the United States. Such charts 

 as are used to illustrate weather conditions 

 are well selected. Nearly every phase of the 

 suhjeet has its appropriate figure or map to aid 

 the student in gaining a correct idea of the 

 matter in hand. 



Exercises. — One of the most important 

 features of the book is the portion devoted to 

 original exercises at the end of each chapter. 

 By the use of these exercises the student is 

 induced to think for himself and apply what 

 is discussed in the text. As far as is prae- 

 . ticable the student is led up into the subject 

 rather than led down out of it. Numerous 

 well selected references are given. These serve 

 a double purpose. Not only do they place the 

 student in touch with more important publica- 

 tions bearing on the subject but they also 

 furnish a list of books which might well be 

 placed in every school library for the use of 

 science teachers. It is a gratification to have 

 such a text-book to work with and it will be 

 appreciated by every teacher of physiography. 



George Burbank Shattuok 



SOCIETIES AND ACADEMIES 



THE NEW YORK ACADEMY OF SCIENCES — SECTION 

 OF GEOLOGY AND MINERALOGY 



At the first regular meeting, October 7, 

 1907, the following papers were read: 



On the Peihles at Harwich {Cape God), Mass., 

 and on Rude Arrow-heads found among 

 them: Dr. Alexis A. Julien. 

 Along the south shore of the apron-plain at 

 Harwich the glacial deposits show abundant 

 sections of layers of gravel, often coarse, and 

 at one point huge angular boulders, up to 

 eight feet in diameter, similar to those in the 

 moraine along the north side of the cape. 

 The pebbles consist almost altogether of crys- 

 talline rocks in considerable variety, in which, 

 however, three types predominate. The prin- 

 cipal one is a coarse binary granite, sometimes 

 porphyroidal, passing by addition of horn- 

 blende into monzonite. Its sheared form 

 seems to be represented by pebbles of granite- 



gneiss or aplite-schist, without mica, and very 

 rarely of a fine biotite gneiss. 



This rock appears to have been cut by intru- 

 sive dikes, both of an acid rock and of another 

 of intermediate character, occurring in abun- 

 dant pebbles. The one is a pinkish quartz- 

 porphyry, a white felsite or finely striped 

 rhyolite, whose sheared form appears to be a 

 white phyllitic gneiss, with minute augen- 

 structure. The other, a rather finely granidar 

 gabbro, made up of white feldspar and a 

 greenish black hornblende-like mineral. This 

 rock by shearing has passed into a hard green- 

 stone, often decidedly schistose, and perhaps 

 into a banded schist. Besides these three 

 types, several varieties of fine crystalline 

 schists, probably metamorphic; rarely small 

 grains of serpentine; and occasional flakes of 

 blue-black argillite. A marked feature in all 

 these rocks is the almost entire absence of 

 mica of any kind and that mineral does not 

 occur even in the sands and clays, at least in 

 scales visible to the naked eye. 



By contrast, the characteristic rocks of the 

 adjoining coast along the mainland of eastern 

 New England have not been found, in spite 

 of constant search, e. g., the mica-gneisses and 

 mica-pegmatites north of New Bedford, the 

 granite of Quincy, Mass., the Dorchester con- 

 glomerate, the pyroxenic rocks and basic mica- 

 diorites of Nahant, the porphyritic biotite 

 gTanites of the Maine coast, etc. The con- 

 clusion is that the pebbles at Harwich have 

 been transported from some other mica-less 

 region. 



Among the pebbles in ploughed fields many 

 rude stone implements may be found, such as 

 tomahawks, scrapers, lance-heads, and particu- 

 larly arrowheads of the simplest form, prob- 

 ably left by Indians of the Massaquoit tribe, 

 of whom several small kitchen-middens have 

 been found in the neighborhood. These tools 

 have been made from the local materials above 

 described, chiefly from pebbles of the harder 

 and finer schists, rhyolite, quartz-porphyry 

 and often granite. Their dull edges and 

 rounded points may imply that in many cases 

 they have never been sharpened, but used for 

 stunning birds and small animals. Many 



