June 17, 1910] 



SCIENCE 



933 



these combined features during a trip by 

 rail from Faenza to Florence in 1899, and 

 then resolved to examine them more at 

 leisure at some later season. On going- 

 there in 1908 we were well rewarded by a 

 delightful prospect over the valley from a 

 favorable view point up on its western side, 

 where our small party of four spent some 

 profitable and memorable hours in the 

 shade of a group of tall cypresses alongside 

 of a little chapel, sketching, drawing maps 

 and diagrams, and discussing our efforts 

 at systematic description. Then we walked 

 over some of the neighboring hills, and in 

 tiie afternoon went by train a short dis- 



outer belt was apparently a continuation of 

 the dissected coastal plain that we had seen 

 by Ancona, here descending by straggling 

 hills to the plain of the Po, instead of end- 

 ing in an evenly retrograded line of sea 

 cliffs. We noted first that in the inner 

 belt of stronger strata the new, early ma- 

 ture valley, incised in the gravel-covered 

 floor of the former, late mature valley, has 

 a well-defined meandering course, with 

 steep-walled amphitheaters in which the 

 inclined strata of the district are well ex- 

 posed, with sloping spurs sharply trimmed 

 on their up-valley side, and with graceful 

 flood-plain scrolls, systematically placed 



Fig. 3. Diagram of the Compound Valley of the Lamone, Italy; looking West. 



tance farther up the valley for new ob- 

 servations. The results are summarized in 

 Fig. 3, an imagined bird's-eye view, look- 

 ing northwest. 



"We thus learned that the valley traverses 

 two piedmont belts of unlike constitution; 

 an inner belt of deformed and somewhat 

 resistant strata, which trend in general 

 parallel to the extension of the mountains 

 in the background; and an outer belt of 

 weak, bedded clays, dipping gently north- 

 eastward. The inner belt seemed to repre- 

 sent the well degraded border of the Apen- 

 nine oldland, with respect to which the 

 outer belt had been deposited; and the 



along the down-valley side of the trimmed 

 spurs. The depth and breadth of the new 

 valley both decrease up-stream, as if the 

 work of the new cycle were less and less 

 advanced as the mountains are entered. 

 As might be expected, the lateral streams 

 that here come down from the dissected 

 uplands have as yet eroded only narrow, 

 young, steep -walled gorges, with abundant 

 outcrops, beneath the soil-covered slopes of 

 the mature lateral valleys of the earlier 

 cycle; but the lateral gorges are already 

 worn deep enough to mouthe at grade in 

 the main valley. We noted secondly that, 

 in the outer belt of weaker strata, all the 



