^ 6 *• '?r~ 



SCIENCE 



New Sbkibs. 

 Vol. V. No. 121. 



Friday, April 23, 1897. 



SiKQLE Copies, 15 cia. 

 Annual Subsceiption, js.OO. 



Geology. 



FIELD WORK. 



Geography. 



IVES STRATA MAP. 



Which graphically exhibits superposition, denudation, and out- 

 crop of strata, with the phenomena of escarpments, outliers, 

 inliers, dip, strike, conformability, etc., while the cards may be 

 bent to show synclinal or anticlinal folds. 



It consists of a series of ten Superposed Maps, representing the 

 Geological Systems of the country, colored as recommended by 

 the International Congress of (Jeologists, portions being cut away 

 agreeably with the distribution of the several systems in nature. 

 The Cardboard Maps are hinged together to admit of examina- 

 tion in detail, while the Archean foundation and the superposed 

 strata are embossed so as to bring all to a plane surface. Size, 



Price, 8 17.50< 



' recommendation (from those who know) are in order, Those who 



" ss the 



IVES ALTITUDE MAP. 



An original device by same inventor and based like the Strata 

 Map upon data of undoubted authority. A novel combination 

 of the two methods commonly employed, viz.: The use of distlnc- 

 tive colors to represent successive levels, and actual embossing. 



Diploma and medal awarded for this also at the World's Colum- 

 bian Exposition. It is beautifully gotten up, varnished and 

 frame. 1 in oak. Light and unbreakable. Size, 33" x 23". 



Prof. E. D. COPE, of the University of Pennsylvania, writes: 

 "Useful to the stadent of topography and geology. The map 

 i'^dicating elevations in relief is an impor ant aid to the strati- 

 graphic map : both together elucidate the structure to the eye of 

 the student." ^j . «» erk 



Price, $9.50. 







" la the study of problems connected with the evolution of the continent, the geologist will realize the increased facility afforded 

 by a method which malses it possible to retoove the layers representing the several systems, at pleasure, reducing the area exhibited 

 to ts condition at any geological epoch, allowance being made for original limitation and subsequent erosion. He will also recognize 

 the advantage of a map constructed of strata which by their superposition convey to the eye and the mind the relative positions In the 

 geological scale of formations wuich they severally represent, avoiding the necessity of constantly referring to the indent, as in the use 

 of ordinary geological maps, or the mental effort and consequent diversion involved in keeping those particulars present to the mind." 

 *,s* 'An Introduction to Geology by itteans of the Strata Map," James T. B. Ivks, F.G.S. (Free on Application.) 

 We owe to Professor C. H, HIT(;HCOCK the only important geological maps of the entire United States available and he writes 

 of the Strata Map : "Am satistted that its use will greatly assist stunents to understand the geological structure of the country." The 

 Director of the United States Geological Survey, CHAS. D. WALCOTT, wrote: "After a careful examination of your Strata Map I 

 very cheerfully state that I approve of its method." His predecessor. Major . I. W. POWELL, wrote: "After examination I am able 

 to state that the work has been executed with care and tidellty." State Geologist, JAMBS HALL, New York, wrote: "Maps con- 

 structed upon tois method would be extremely useful." state Geologist, J. P. LKSLEY, Pennsylvania, wrote: "A piece of new and 

 useful apparatus for teaching Geology, by representing to the eye of the student the areas of superimposed formations, 1 cordially 

 recommend it " Beside the present and late directors of the U. S. Geological Survey, other distinguished members testified as follows: 

 C. E. DUTTON: "An excellent method of representing the facts of stratigraphlc Geology, and very valuable as a means of instruction 

 in Schools and Colleges." «. K. GIL BERT : "The desideratum Is a eraphio method for the joint expression of horizontal and vertical 

 distribution and the Strata Map makes an important step in this direction." W. J. McGEE (a high authority on the point) : " I have 

 examined with pleasure your Strata Mao of eastern United States based upon my map and find that it quite fully represents the geologic 

 structure of the country as far as ascertained." The late Professor ALEX ANDER WI NCHELL, who did so much by his writings and 

 lectures, to popularize geology, wrote : "It seems to me that the device will commend the study of Geology to many persons who might 

 otherwise regard the subject as difficult and uninviting." 



ADDRESS ORDERS AND ENQUIRIES TO 



JAMES T. B. IVES, Care of SCIENCE, 66 Fifth Avenue, NEW YORK CITY. 



