Books with author Bil Gilbert

Excerpt from The Subways and Tunnels of New York: Methods and Costs, With an Appendix on Tunneling Machinery and Methods and Tables of Engineering DataThe ferry systems from New Jersey, Long Island and Staten Island have reached the limit of their capacity. The East River bridges furnish relief to the situation, but are by no means sufficient. The elevated and surface car systems of New York and Brooklyn have been extended to their practical limit. With surface, above - surface, and over-water means of transit incapable of further expansion, the only alternative was to make use of the subterranean and subaqueous territory underlying and adjacent to the greater city. The. Subways, and sub aqueous and land tunnels, in and about New York City maybe considered as simply a beginning of a vast system of subsurface transportation which must develop with the growth of population.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

The juvenile hormones of insects are unique molecules in terms of their chemical nature (methyl esters of sesquiterpene epoxides) and action (both as modulators of morphogenesis during the larval life of insects and as a gonadotropic agent in many female adults). Although a symposium dedicated to the chemistry, metabolism and effects of juvenile hormone at a number of levels would be merited on the basis of its interest to the chemist, physiologist, endo­ crinologist, developmental biologist and entomologist, the juvenile hormones are special in the sense that juvenile hormone mimics (juvenoids, insect growth regulators, analogs) are currently being utilized to control various insec. t pests. Indeed, a number of commercial firms are currently developing new compounds with juven­ ile hormone activity that might possess a narrow spectrum of acti­ vity and which would be relatively biodegradable. Thus, a symposium on the juvenile hormones is also merited on a practical basis since juvenoids are already becoming constituents of our environment and it is apparent that in order to design effective mimics of the natural juvenile hormones, o~e should understand the means by which juvenile hormone elicits its effects. As will become evident to the reader, the great majority of data presented at this symposium have not been published previously and the symposium itself was organized along natural divisions dealing with the chemistry, metaoolism and multi-level modes of action of the juvenile hormones. Special lectures were presented by Professors C. M. Williams, B. W. O'Malley and W. S.