SCIENCE. 



[Vol. XIV. No. 335 



garbage and house-sweepings, which heretofore were regularly 

 burned with the solid fuel then in use, can no longer be disposed 

 of in that way ; and after various unsuccessful attempts to bury 

 them, deposit them in the rivers, and burn them in open air, a num- 

 ber of specially designed furnaces were built for the destruction of 

 these accumulations, to which are now added the offal from 

 slaughter-houses, the leached-out bark from tanneries, and all 

 garbage from the public markets. The heat created by the com- 

 bustion of these waste substances is successfully utilized for gen- 

 erating steam in boilers attached to the furnaces, which, without 

 the addition of any other fuel, except what is required for ignition, 

 supply the motive power for operating the machinery in adjoining 

 factories; so that these establishmenls not only improve the sani- 

 tary condition of the community by the prompt and radical destruc- 

 tion of vegetable and animal refuse, otherwise liable to decay on 

 our hands, but also furnish a cheap fuel-supply for industrial pur- 

 poses. 



Streets and Highways. — Nearly all the larger cities of this 

 country have now passed the experimental stages of their street- 

 paving experiences, and have by this time entered upon a period of 

 more permanent and substantial improvements in that department 

 of municipal engineering. The days of wooden roadways, the 

 Nicholson, the cedar, and locust blocks, will soon be remembered 

 only as things of the past, like plank roads of earlier date. The 

 various compounds with which, at one time or another, nearly all 

 our city streets have been plastered over and poulticed, have 

 cracked and split, shrunk, melted, and evaporated, and been carried 

 off piecemeal, in course of time, by the persistent adhesion of their 

 ill-flavored mixtures to the boot-heels of the weary pedestrians in 

 hot weather. The abominable cobble-stones, which have jarred 

 our nerves and dislocated our spinal columns in years gone by, are 

 finally relegated to the by-streets and back alleys. Such make- 

 shifts may answer the purpose for a while in new towns of rapid 

 growth, where better materials are not readily attainable, and 

 where first cost is a paramount consideration ; but they should 

 never be renewed to the extent that has been the case so often, in 

 spite of the most convincing experience, and contrary to the best 

 counsel of professional advisers. The sums of money wasted in 

 repeating these mistakes would in many instances have gone far 

 towards carrying out much more permanent and substantial im- 

 provements. 



For streets in the vicinity of freight-stations, or of manufacturing 

 establishments employing heavy teaming, and for streets with 

 steep gradients, pavements should be made of stone blocks of 

 basalt, trap-rock, granite, or hard limestone, laid upon a bed of 

 broken stone ballast, topped off with sand or fine gravel, well 

 rammed, and joints filled with cement grouting or coal-tar; for 

 streets used by lighter traffic or carriages only, a well-laid pave- 

 ment of pure asphalt upon a bed of stone ballast answers the pur- 

 pose very well, if prompt attention is given to the maintenance and 

 necessary repairs ; for parks and suburban pleasure-drives, a good 

 macadamized road, well drained, and constantly kept in condition, 

 affords a very superior and comfortable highway. 



Of late years, pavements of hard burnt fire-clay brick have been 

 extensively laid in many cities and towns of the Middle States, 

 where the supply of this material is very abundant and remarkably 

 cheap. In some towns of West Virginia and eastern Ohio such 

 pavements have been laid for less than a dollar per square yard. 

 They make smooth roadways, are easily kept clean, and last very 

 well under moderately heavy traffic. This pavement is especially 

 well adapted for cities of medium size, which cannot well afford more 

 expensive kinds, and yet require something more substantial and 

 durable than either asphalt or macadam. 



But if there is one thing which needs reformation more than any 

 other, it is the condition of our common country roads. If it is 

 true that the highways of a people are a measure of their civiliza- 

 tion, then we cannot complain if we are classed as an inferior type 

 of low barbarians. The good nature with which we submit to the 

 imposition of the annual road-tax is only equalled by the sublime 

 resignation with which we accept the result of the effort which 

 swallowed up our money. Our Western members all know what 

 is meant by " working the roads." It means to plough a furrow 

 on each side, and scrape the mud into a ridge in the middle, simply 



to be washed down again into the ditches by the first shower of 

 rain. And this performance is repeated year aft«r year, under the 

 provisions of our statutes, and by the consent of a law-abiding 

 but much-suffering people. During the spring and fall, we struggle 

 through the mud manfully as best we can ; and when winter comes, 

 and the bottom- literally drops out of the roads, we quietly compose 

 ourselves, and contentedly stay at home. 



Some years ago, while out on an exploring expedition for a rail- 

 road in southern Ohio, I was compelled to hibernate, so to speak, 

 with my entire party, for nearly a month, in a lonely village among 

 the hills of Wills Creek in Noble County ; and, when I made an 

 effort to advise my employers of our situation, I was cheered by 

 the comforting assurance of the postmaster that my letter would 

 certainly go out just as soon as the roads dried up. 



A faint ray of hope, however, is just beginning to dawn in some 

 parts of the country, most conspicuously in Ohio, where, under the 

 provisions of a recent law, a number of free turnpikes are being 

 built, of quite a superior character, by special tax levied upon the 

 adjacent property. 



The beneficial results of this wise system of improvements are 

 very great, and highly appreciated by the people, and it is sincerely 

 to be hoped that other States will profit by the example. 



Canals and Hydraulic Engineering. — The days of ordinary 

 canal navigation in the interior parts of this country may well be 

 considered as numbered with the past. With the exception of the 

 Erie Canal, which still maintains to some extent its character as a 

 waterway of commerce, and excepting some parts of the canals in 

 eastern Pennsylvania, New Jersey, Maryland, Ohio, and Illinois, 

 these primitive transportation lines have either been abandoned en- 

 tirely, after outliving their short period of usefulness, or thev are 

 now merely utilized for carrying bulky products between local 

 points, or for the supply of hydraulic power to manufacturing 

 establishments. 



Still more discouraging are the immediate prospects for the vari- 

 ous maritime canal projects. The Panama Canal, upon which very 

 large sums of money have been expended, has finally been aban- 

 doned, after many unsuccessful efforts of its projectors to raise the 

 funds still required for its completion, and after, as a last resort, 

 modifying the original plans of a sea-level canal to one with locks. 

 But notwithstanding this momentary failure, I most sincerely hope 

 — and I honestly believe — that it is yet reserved for American 

 engineering skill and American enterprise to resurrect and success- 

 fully carry forward this great and important project to its ultimate 

 completion. 



The Tehuantepec Ship Railway, which, for the purpose on hand, 

 may properly be classed with the maritime canals, has not met 

 thus far with the encouragement which its importance and the un- 

 qualified indorsements of eitiinent professional talent would seem 

 to justify. Probably the sad fate of its Panama rival, which places 

 it for the present out of the range of active competition, may assist 

 in reviving the ship-railway project to which our lamented fellow- 

 member, the late Capt. Eads, devoted his energies during the last 

 years of his useful life. 



New interest is being manifested in the old ship-canal project 

 across the Isthmus of Nicaragua, which, in the matter of demon- 

 strable feasibility, undoubtedly has many points in its favor. 



Among other ship-canal projects in active progress may be 

 mentioned the Cape Cod Canal, which was commenced in 1880, 

 and which will, when completed, connect the Bay of Cape Cod, by 

 way of Herring River, with the head of Buzzard Bay in Massa- 

 chusetts. 



The magnificent success of the ship-canal at Sault Ste. Marie, not 

 only as an engineering project but also as a commercial enterprise, 

 has surpassed all expectations ; and since its completion the traffic 

 upon the northern lakes has been multiplied to such an extent that 

 it has been found necessary to build an additional canal and a new 

 lock of larger dimensions even than the one now in use. The 

 direct impulse given by the completion of this canal to the lake 

 navigation, and the indirect effect upon the general business of that 

 region of country, have stimulated the work on the hydraulic canal 

 at Sault Ste. Marie, from which great results are expected ; and they 

 have also hastened the operations in progress for deepening and 

 widening the channels through the shallow parts of Hay Lake, 



