394 Scientific Intelligence. 



suits, to the rainette dike of Franklin Furnace, New Jersey. The 

 mathematical foundation has also been worked out for him anew 

 by Prof. Woodward, with accordant results, but whereas I treat 

 the case where the country rock is appreciably heated up, he 

 takes only the case in which the walls of the cooling body are 

 kept at a constant temperature. 



Unfortunately we have taken different initial temperatures, 

 and otherwise the two methods differ so that the curves and 

 numerical tables cannot be directly compared. The curves of 

 falling temperature given in my paper are referred to the time, 

 whereas in Queneau's paper the abscissas are laid off proportional 

 to the square root of the time. The early stages of cooling are 

 given, therefore, in more detail, but his remark at the bottom of 

 page 188 as to the slopes of all the curves being equal, is errone- 

 ous. It applies to my curves, but not to his.* Queneau's results 

 upon the minette of the Franklin Furnace are especially note- 

 worthy; both biotite and apatite vary in size according to the 

 distance from the margin. This shows clearly that these min- 

 erals are mainly not pre-intrusive. Moreover, the size of the 

 apatite increases, clear to the center, while the biotite has a zone 

 of nearly uniform grain occupying nearly the middle two-thirds 

 of the dike. The following inferences of theoretical interest, 

 which, however, Mr, Queneau does not mention, may be drawn: 



The apatite was formed early, much before the biotite, and 

 probably before the dike had lost even one-tenth of its initial 

 temperature. The dike therefore must have been largely viscous 

 when the apatite formed, and the broken condition of the apatite 

 mentioned by Queneau may well be attributed to a strain in the 

 otherwise viscous magma. 



The biotite was formed later, and supposing, as seems likely 

 from the figure, that the breadth of the zone that has a markedly 

 less grain than that at the center is about one-eighth of the width 

 of the dike, we must infer that it was formed when the dike 

 retained but little more than half its initial excess of tempera- 

 ture. 



A small dike of diabase, a meter wide, shows in its feldspars 

 that the temperature of its injection was not much above that of 

 the formation of feldspar, at any rate. 



When he discusses the Palisade trap sheet, however, Mr. Que- 

 neau neglects to mention that he does not carry his section clear 

 across, nor does he state the thickness of the sheet, nor say 



* Some other minor mistakes in our papers are : on page 187, one column 

 should be headed x= 'Soc, and line five above should begin with -Ooc. I be- 

 lieve there are also some numerical mistakes in the body of the tables. The 

 last column of the table on page 188 is erroneous, for instance. Also on 

 page 191 the units for x are not in square but linear millimeters. In my 

 table, when m=7 if g = '92, the entry should be '74265, and if q is "91 the 

 entry should be "73000. In my equation 11 an n has crept in that does not 

 belong there, and on page 117, line 2, for {w) read {2iv). Also, in the plate, 

 the decimal point for the horizontal unit is wrongly placed, — it should be 

 logg= -O-l. 



