DISCIPLINARY VALUE OF GEOGRAPHY 237 



the other two named the Nera and the Teverone; that the Tiber delta 

 has been prograded about fifteen kilometers from the original river 

 mouth at the outer side of the volcanic saddle ; and so on. Thus at the 

 end of eight or ten minutes, the hearers will be well prepared for any 

 details that may follow ; details, for example concerning various smaller 

 calderas in the truncated volcanic cones; or concerning the meanders 

 of the Tiber; or concerning the origin of the cascades at Tivoli by 

 travertine aggradation at the mouth of a formerly normal and mature 

 valley in the limestone range east of Eome. Each detail will fall easily 

 into place, and take proper rank among its fellows. 



When it is remembered that, however accurately the features of a 

 region may be known to the geographer who has studied them on the 

 ground, they can — apart from maps — become known to those who have 

 not been on the ground only through such report as the observer may 

 give concerning them, it will be recognized that the attention here 

 directed to the art of presentation as a supplement to the science of 

 investigation is fully deserved. 



Printed Reports. — If allowance is made for the necessary contrasts 

 between oral and printed presentation, as summarized at the beginning 

 of this supplement, the suggestions given above as to the different 

 st}'les of presentation for reports on geographical problems may apply 

 to printed essays in scientific journals, as well as to spoken communica- 

 tions made at scientific meetings: but there are certain additional fea- 

 tures of printed reports, especially if they are long and detailed, which 

 deserve consideration. In preparing such reports, it must be borne in 

 mind that an enormous amount of printed matter is issued in these 

 modern times ; and that even within the limits of a single science there 

 is much more material published than can possibly be read by any one 

 man. Hence if the author of an essay desires to increase his chance 

 of gaining the attention of his colleagues, he ought to give particular 

 attention to making his text easily intelligible. Several recommendable 

 means of realizing this object may be briefly stated. 



In long and detailed essays, it is extremely helpful to the reader 

 to find a summary of contents presented in an introductory paragraph. 

 The value of such a summary here is much the same as at the beginning 

 of an oral report : it enables the reader, when he comes to the later pages, 

 to perceive the bearing of each part on the whole. A sunmiary at the 

 end of an essay by no means takes the place of one at tiie beginning; 

 for the author who places a summary only at the end of his report evi- 

 dently regards that as the proper place for its reading; and hence pre- 

 pares it in a style which may be easily understood at the end of the 

 article, but which is necessarily quite unlike the style of an opening 

 summary that is to be read as an introduction to everything that 

 follows. Two summaries, one at the beginning in proper introductory 

 phraseology, and one at the end in much more specialized phraseology, 



