780 



SCIENCE. 



[K S. Vol. XXIV. No. 624. 



from down upward and make all tight. Re- 

 peat at will, working always toward the right. 

 I am now writing up the Dr. W. L. Abbott 

 basketry, from southwestern Malaysia, and 

 desire to use nomenclature that will stand for 

 the Philippines, where the * Malay knot ' is in 

 vogue. The trouble with the name is two- 

 fold, there are other Malay knots and other 

 peoples who use the same knot. Perhaps 

 * Malay double hitch' would be better, but it 

 is somewhat nautical. 



O. T. Mason. 



THE RIGIDITY OF THE EARTH. 



Professor See's computation of the mean 

 hydrostatic pressure within the earth, deduced 

 from Laplace's law of density, is doubtless 

 correct. That the modulus of rigidity is 

 equal to the hydrostatic pressure is, however, 

 purely an assumption. 



L. M. HosKiNs. 

 Palo Alto, Cal., 

 November 10, 1906. 



THE LIGHTNING-ROD COINCIDENT WITH FRANKLIN's 

 KITE EXPERIMENT. 



A FILE of the Pennsylvania Gazette for the 

 year 1752 furnishes facts which corroborate 

 my conclusions, in Vol. XXIV., pages 374- 

 376, that the lightning-rod was in use about 

 the time Benjamin Franklin flew his elec- 

 trical kite. The supposition there discussed, 

 that the news of the successful experiments 

 in France by MM. Dalibard and Delor during 

 the month of May did not reach Philadelphia 

 in June, during which month Franklin is said 

 to have brought down electricity from the 

 clouds, is supported by the fact that a letter 

 from Paris describing the French experi- 

 ments, and dated May 26, N. S., 1752, was 

 not published in the Pennsylvania Gazette 

 until August 27 of the same year. 



That Franklin did not fly his kite until 

 later in the summer than June is likewise 

 indicated by the circumstance that the first 

 account of the experiment appeared in the 

 Gazette of October 19. This account is 

 identical with the oft-quoted letter to Peter 

 Collinson, which was read before the Royal 

 Society iji December and printed in the Philo- 



sophical Transactions, excepting that it lacks 

 the closing statement about the experiments 

 in France with ' points ' and their prior use 

 in America. 



Finally, my assumption that the directions 

 for erecting lightning-rods, which appeared 

 in Poor Richard's Almanac for 1753, must 

 have been written not later than October, 

 1752, is proved correct by an advertisement 

 in the Gazette of October 19, stating that this 

 issue of the Almanac was in press and would 

 be published shortly. 



The collateral evidence here adduced favors 

 the belief that Franklin performed his kite 

 experiment some two months later than has 

 been supposed, and proves conclusively that at 

 the time when it was first described Franklin 

 had already prepared for publication precise 

 directions for placing lightning-rods upon all 

 kinds of buildings. 



A. Lawrence Rotch. 



Blue Hill Meteobological Obseevatoey, 

 November 1^, 1906. 



SPECIAL ARTICLES. 



notice of a new MIOCENE RHINOCEROS, 

 DICERATHERIUM ARIKARENSE. 



The accompanying sketches represent the 

 skull of a species of rhinoceros, Diceratherium 

 ariharense, supposedly new, discovered by the 

 geological expedition of 1905, sent from the 

 University of Nebraska by the Hon. Charles 

 H. Morrill to the Loup Fork beds at Agate, 

 Nebraska, on the ranch of Mr. James Cook. 



The genus Diceratherium was established 

 by Marsh in 1875 on material from the Mio- 

 cene beds near the John Day River in eastern 

 Oregon, and two species, armatum and nanum, 

 were recognized. A third species, advenum, 

 was based on material from the Eocene (pos- 

 sibly Miocene) of Utah. Difference of hori- 

 zon, and distance seem to warrant the specific 

 name herein proposed. In comparing numer- 

 ous individuals such variation was noted as to 

 justify the belief that this group might legiti- 

 mately enough be divided into several species. 



The figures seem sufficiently explanatory, so 

 descriptions will be brief. A pair of anterior 

 protuberances or horn cores constitute the dis- 



