United States Circuit Court--District of Maryland. THE AMERICAN BALLAST LOG COMPANY OF NEW YORK VS. BARNBS et at. In equity--efore Judges Bond and Morris. PATENT No. 136,938--BALLST LOGS--PATENT.--The complainants' device is essentially a combination of two counterbalance weights, and cannot be construed to cover all m ethods by which vessels may be kept in an upright position while in port, by means of contrivances fastened on the outside and floating in the water, but only such as are sub-stantially identical with the device described in a patent in construction, form, and principle of operation. Defendant having dispensed with one of the essential elements of the combination, and having substituted therefor a new mode of accomplishing the same object, not a mechan i-cal equivalent, and not similar in principle of operation, there is no infringement. Bill dismissed. Financial and other Results of the Recent International Exhibition of Electricity at Paris. Mr. Cochery, the Minister of the Post and Telegraph Department, lately addressed a report to Mr. Grevy, Presiden t of the French Republic, giving a recapitulation of the financial results of the exhibition held last year in Paris, and this summary has just been published. 8e of its most essential points will be of interest to American inventors and other participators in the Exhibition. Mr. Cochery says: " In face of a recess of the Chamber of Deities we were un able to engage the state in eventually paying certain sums in case of debts being incurred ; at the same time it would have been impossible to wait till the assembling of the deputies before beginning the preparatory work. " people having liberally offered to guarantee the state against any losses which might be entailed by the Exhibition after deducting the receipts it produced, we were e nabled to accept these propositions, which protected the state against any eventuality, and were h appily able to invite the different nations to take part in the Exhibition. " The association formed for the purpose of carrying out this Exhibition, guaranteeing the state against loss, at the same time stipulated besides, that in case the receipts of the Exhibition be grcater than the expense incurred the balance should be remi tted to the government, to be employed hy the same in woAs profitable to the electric light. "The Exhibition was opened on the 10th of August, and though in the beginning all was not finished, fifteen days had not elapsed before the completeness of arrangera ent was perfect. "From the 27th of August the Palais of Industry was illuminated by electric light every evening. "TJe number of exhibitors was 1,764, of which 937 were Frenchmen and 827 w ere foreigners. "The number of visi tors who bought cards of entry was not less than 673,473. Free entry was permitted to a great many. Cards were distributed most liberally to schools, workshops, etc., and the last days of the Exhibition were devoted to the public gratuitously. During these two days more than 80,000 people were able to profit by this liberality. " The law of the 27th of December, 1880. accorded a su bven-tion of 200,000 francs, and to this sum 25,000 francs were added by the city of Paris; to this add the receipts, and we find the sum total of the Exhibition's treasury to have been 1,048,417.68 francs; actual expenses, 689,490.84francs. From this it results that a net profit of 358,936.84 francs was made, and after having settled a few debts still unpaid the remainder will not be less than 325,000 francs. It is this sum, the subvention by the state of 125,000 francs dedu cted. that will be returned to the government with the prayer that the same be used in creating a laboratory of experimen tal electricity." Mr. Cochery then proceeds to recommend that this petition be granted, as he considers that the signature of the President affixed to a deed or decree carrying out the idea the petition designates, will be a perfect completion to favorable results .attained by the Exhibition, and thus be an encouragement for those who in future .undertake to carry out exhibitions. _ The collection of electrical machines and implements at the Palace of In du s t ry proved what immense progi'css has been m ad e in el ectricity within the last few years, and the establishment of a central laboratory of electricity will furnish the means, in France at least, to develop this science, the future of which is so vast. The laboratory will in a modest way continue the work of the Exhibition, and will be under the supervision of the Department of Post and Telegraph, the departmen t that organized the Exhibition of Electricity. Mr. Grevy has signed the necessary decree, and has thus established the new laboratory of electricity, sanctioning the use of the net balance of 325,000 francs produced hj the Exhibition to found and support this new bran ch of the Post and Telegraph Department. This is the way science and art are encourawi in the Old World. People are willing to pay high taxes when the .state makes some show of genei-osity in such public matters as appertain to science, art, and the industries. G. Insuring the Insurance Companies. Edward Atkinson and William B. Whiting send the following timely suggestions to the members of the Boston Manufacturers' Mutual Fire Insurance Company: It is impossible for any man who takes an interest in the profession of mutual underwriting not to endeavor to cope with the dangers of great conflagrations, which are day by day becoming greater in our large cities, even though the factory mutual companies have no direct interest in the matter. The only d rawback to the pleas ure of conducting a sys-of insurance--the objective point of which is not merely to pay an indemnity for loss, but much more to save property from destruction by fire--is that it becomes a habit to look at every building in process of construction with a critical eye, and one is apt to lose patience ill witnessing the waste of money in unsafe methods, where the simplest rules of safety would save large sums even in the cost of building. The handsome and well composed fronts of warehouses and hotels, and the apparent solidity of churches and school-houses, cease to give any pleasure or satisfaction, even as works of artistic design, when we know that every part of the interior is so constructed as to assure heavy damage or complete destruction if a fire happens in any part of the premises; while the surveys which we have occasionally been asked to make, with a view to preventing the destruction of insane asylu m s and hospitals, leave an unpleasant impression of almost criminal stupidity and ignorance in their mode of construction, and in the arrangem en ts of the fire apparatus. Not only does the danger to property demand attention, but the dan ger to life c ompels it; and any true man would lose all self-respect who did not use what little influence he might possess, and urgently present the lessons learned from his experience, in an endeavor to prevent disasters which may occur at any moment--such disasters as have lately occurred at the destruction of the theater in Vienna, at the recent fire in New York, and in other recent instances which need not be mentioned. Destructive fires in theaters almost invariably begin amidst the combustible materials upon and over the stage; the scenery is iiot only of necessity combustible, but the materials which are in constant use, such as paints, oils, light wood, canvas, and also the processes of use, of renewal, and of repair, are all of a nature which the mutual underwriter would regard with the utmost distrust, and would only insure at all when every available means of precaution have been taken for extinguishing the fires which experience lias absolutely proved will occur at comparatively short intervals in such stock, either from accident from without or spontaneous combustion within the mass. We believe this dan ger may be guarded against with almost absolute certainty by placing automatic sprinklers over and around the stage of any theater, and we hope we may have so impressed the Police Commissioners of Boston with the probable efficacy of this apparatus as to cause th to make its use compulsory under the authority recently given them. But inasmuch as every member of this company has a money interest in the safety of the commercial districts of Boston, New York, and Philadelphia, no apology is needed for again enforcin.g the necessity of more adequate means of preventing loss, especially in New York. A com pu tat ion has recently been made that in one small section, comprising an area little, if any, over two acres, there is seventy million dollars' worth of property at risk; this may be an exaggerated esti mate, but there are many acres up on each of which five to ten million dollars' worth of property is at risk. During the daytime there is no head of water immediately available in this district, and the multiplication of wires is daily rendering it more difficult to raise ladders at the right places; this again causes great delay in carrying up lines of hose and in getting the water upon the fire in such a way as to do any good. In view of these facts, attention may again be called to the entire feasibility of attaching permanen t 4-inch iron pipes to the corners of blocks, and carrying a 4-inch iron pipe service with hydrants at every pay-wall over the whole area of the roofs con stituting a square or block of buildings; such apparatus to form a part of the public fire service, and to be used by the public fire department only, cou pli ngs being attached to the base of the vert i cal pipes by which a connection may be made with the steam fire engines. It may be useless to repeat this suggestion, but in view of the accumulation of wires, and the possible new dangers from electric light wires, a quick supply of water upon the roofs of our high buildings is becoming more and more necessary. At the time this suggestion was first made such a roof hydrant service, with the necessary vertical pipes, could have been put up, ready for use, at a cost of $1,600 to $2,0ij0 an acre; it might now cost a little moio. If there are acres upon which the insurable value of the property ranges from five to thirty-five million dollars, then a sum ranging from $25,000 to $250,000 a year is paid out in premiums of insurance upon each of such acres, and if from one to ten such acres were burned, then from ten to fifty per cent of the indemnity promised under these policies of i nsur arice would not be collected ; witness the value of similar policies after the fires in Chicago and Boston. It may well be asked if it would not be worth two or three thousand dollars an acre for a service of roof pipes and hydran ts, for tbe mere purpose of insuring the insurance companies, which may otherwise be made' bankrupt by a fire covering only a small part of either of th e great commercial districts of the cities named. It may also be a matter of interest to observe the fact that if there are acres in the crowded part of the dry goods district of New Yo upon which a sum even approximating $250,000 is annuall,y paid for insurance, a single year's premium might suffice to pay the cost of a pumping station on one of the docks, and of a special main pipe leading to that specific acre O\J. The first answer to these suggestions always is, that no concessions can be had in the rates of insurance now charged if these precautions are ado pted ; to which it may be answered that no concession s out to be made upon rates which are already so low as to preclude the accumulation of any adequate reserve, and which are depleted from 30 to over 50 per cent by the mere expense of conducting the competitive system of insurance as now practiced. But the more complete reply is this: that the man who accepts or rejects provisions for the safety (if the premises in which he has a money interest, merely on the single issue of the rate of premium charged, is not a safe man to be insured at any price. The difficulty, which really lies in the way of adequate measures for protecting the concentrated hazards of cities, is in the difficulty of promoting co-operation among owners. City governments, as now constituted, are almost unfit to do the neces wry work. and individual owners seem silmost incapable of making the necessary com binations. If a conflagration exceeding the Chicago and Boston fires should happen to precede a financial crisis more severe than that of 1857, if not as much prolonged as that of 1873, some action m possibly be h oped for in the protection of warehouses already built. In the meantime it is a satisfaction to note that more attention is being given to safer methods of construction in man y of the more recent buildings, while the old stock of combustible churches, hotels, schoolhouses, hospitals, and asylums is being consumed at an accelerated rate; the normal rate of destruction of previous years of one church per week, and one almshouse, insane asylum, or schoolhouse per month, having been considerably exceeded during the year 1881 iu the United States. The period of combustible architecture appears to be near its end, and in another generation the masters of that art may have yielded place to the better instructed graduates of the present day. The Telephone for Finding Springs of Water. A new use for the micro-telephone has been devised by Count Hugo Von Euge nOerg, at Cas tie 'l'ratzberg, in the Tyrol, namely, for finding underground watercourses. At several different places on the declivity of a hill, he buries a number of microphones in the soil. and connects each of them with a battery and a separat e telephone. In the night, w h en other sources of d isturban ces are wanting, or less noticeable, he listens at the telephones, and is enabled to detect in this manner the faintest murmur or gurgling of water within the earth to a considerable depth. The microphone plays the part of the sensitive ear of hunter or savage, who is often able to d etect the presence of wate r in the same way. The Pioscope-Prof. Heeren's Milk Test. This newly invented imtrument, the " pioscope," consists of a disk of black vulcanized caoutchouc, having in its middle a very flat, circular depression. A few drops of the milk in question, well mixed, are placed in the hollow and covered with the second part of the apparatus--a plate of glass painted with six shades of color radiating out from a small uncolored circular spot in the middle. The colors range from white gray, to deep bluish-gray. The layer of milk is seen through the uncolored spot in the center, and its color can thus be compared with the radiating colors. and its quality is judged accorrling to the color with which it coincides. Thus the white* color stands for- cream, the next for very rich milk; then follow, in succession, normal, inferior, poor, and very poor.