AutomaticMixing Valve for Bathing Water THE accompanying illustration shows a unique German electrically-operated mixing valve by which any desired warm water temperature may be kept constant. It is adapted for use in large institutions, such as baths, sanitariums, and the like, as well as for various industrial purposes where constant temperatures are required. It will be observed that the temperature is controlled by a thermometer whose bulb reaches into the pipe containing the mixed hot and cold water. This thermometer is provided with platinum contact points connected to a double-switch lever, which may be set for the maximum and minimum temperature desired. This double switch may be seen directly over the bath tub in our illustration. Wires run from the switch to a set of relays, shown at the left-hand side, which. control the circuit of a motor that operates the mixing valve. This valve connects either the hot water pipe or the cold water pipe or both with the mixed water supply pipes. The operation of the device is as follows: If it be desired to keep the temperature within the limits of 78 degrees and 82 degrees Fahrenheit, the two switch levers are adjusted accordingly. Thereafter, the apparatus operates automatically. If the temperature in the pipe with which the thermometer connects is below the minimum, the circuit of the motor will close automatically, opening the valve to the hot water supply until the temperature of the mixture has been raised to or above 78 degrees. If the mixture grows warmer than 82 degrees more cold water will automatically be supplied. A large number of bath tubs may be supplied through a single mixing valve and the temperature of the water supplied to each tub will automatically be maintained between the predetermined limits. Removable Ambulance Linings TTWERY hospital for contagious diseases -L-'is now and then confronted with the serious problem of transporting persons without the loss of time necessary for proper disinfection of its ambulances. Many different patients, each suffering with a different disease, are received daily. Of course it is impossible to maintain a separate ambulance for each disease. A solution of the difficulty has been provided by the superintendent of a hospital in Buffalo. He has had five linings made which may be fitted into any of the hospital ambulances. One of these is used for scarlet fever cases only; another for diphtheria; another for measles; another for smallpox, and the fifth one for special suspected cases, or for other diseases not mentioned. These linings are stored in separate metal air-tight compartments built on a semi-circular platform at the edge of the garage turntable. The linings can either be disinfected in the ambulance, as all openings are made to shut tight, or they can be removed from the vehicle, placed on the ground and washed with soap and water. They may also be fumigated while in their storage compartments within the garage. Two men can exchange an infected lining for a clean one in five minutes. Thus a single ambulance is made the equivalent of five. While this invention was originally designed for use by hospitals handling contagious diseases, it would no doubt be a benefit to the general hospital as well, because the latter is often called upon to transport patients supposed to be suffering with some simple malady, who, upon examination, prove victims of some dangerous and infectious disease. The advantage of using separate linings have been increased by the recent almost universal adoption of motor ambulances, which has rendered fumigation difficult, and washing almost impossible, because of wetting the electrical connections. Particulars of the New Zealand Government's Offer of a Bonus of £12,000 (Nearly $60,000) in Connection With New Zealand Hemp THE New Zealand Government has agreed to pay £12,000 (about $60,000) as a bonus or bonuses for improvements in connection with— 1. The extraction and dressing of fiber from the New Zealand hemp-plant (PhorwwuTO tenax), or 2. The utilization of the by-products obtained during the processes of extracting the fiber, on condition that the machine or process in regard to which the whole or any part of the bonus is to be paid shall be recommended by the New Zealand Flaxmillers' Association, and approved by the Government. The £12,000 will be paid, wholly or in part, for any of the following, viz.: 1. A process of extracting ana dressing the fiber of New Zealand hemp (Phormium tenax), whether by machinery or otherwise, whereby there shall be obtainable (a) a greatly improved quality of fiber marketable at a higher price, or (b) a substantial reduction in the cost of producing the fiber. 2. Any such process that shall produce a fiber fit for use in manufactures other than rope and twine spinning. 3. Any such process that shall render unnecessary any of the present operations involved in extracting and dressing the fiber, such as stripping, paddocking, or scutching. 4. Any improved method of separating the green envelope or the flinty or colored matter from the green leaf of the phormium plant so as to produce a strong white fiber the whole of which can be saved with little or no tow or waste. 5. Any means whereby the by-products obtained during the processes of extracting and dressing New Zealand hemp-fiber—such as the gum, dye, stripper-slips, tow-dust, or waste vegetable matter—shall be converted into a marketable commodity. Applications for the bonus must be addressed to the President of the New Zealand Flaxmillers' Association, Palmers ton North, New Zealand, and must reach him not later than noon of November 30th, 1913. They must be inclosed in an envelope clearly marked “Application for bonus. “ Each applicant shall state what lump sum (including the bonus of £12,000 or any part thereof) would he required to purchase the New Zealand rights of his machine or process in the .went of such rights being acquired by tho New Zealand Government for free use by the hemp-millers of the Dominion; or, if any applicant is unwilling to sell his rights, he shall state what amount of bonus (not exceeding £12,000) and what royalty he would require for the use of his machine or process. As soon as possible after the expiration of the time for receiving applications for the bonus (November 30th, 1913) the Flax-millers' Association shall appoint a committee of not less than six of its members to open and examine the applications, to test such of the competing machines or processes as it considers worthy of trial, and to make recommendations to the Government as to the payment of the bonus. Each applicant must give, at his own expense, such reasonable demonstrations of the working of his machine or process as shall be demanded by the said committee, and such demonstrations shall take place in some convenient locality in New Zealand selected by the committee. The Committee shall notify the Secretary of the Department of Agriculture, Commerce, and Tourists at least fourteen days beforehand of the time and place appointed for such demonstrations, and shall allow any accredited representative of the Department to fully examine the working of the machines or processes that are being demonstrated. It should be noted that nothing in these conditions prevents a machine or process placed on the market prior to November 30th, 1913, from competing for the bonus?. On completion of all the demonstrations it deems necessary, the committee shall consider the whole of the machines or processes submitted for competition for the bonus, and in doing so shall take the following matters in connection with each one into consideration: 1. The amount of the lump sum or royalty required for the rights. 2. The cost of purchasing, installing, and operating. 3. The labor and time occupied in operating. 4. The labor and time required after the operation and before the product is ready for packing. 5. The cost of producing the fiber, tow, or other product. 6. In the case of machines or processes for extracting and dressing the fiber, the percentage of fiber, and tow if any, produced from a given weight of green leaves. 7. In the case of machines, the sim- plicity, durability, and safety of the working parts. After considering the whole of the applications in the above respects, the committee shall forthwith submit to the Honorable Minister of Agriculture a report showing— 1. A complete list of all the applications received, giving the name and address of the applicant; the nature and purpose of the machine or process; the nature and value of the product; the quantity produced; the lump sum or royalty required for the rights; the estimated cost of purchasing, installing, and operating; the estimated labor and time occupied in operating; the estimated labor and time required after the operation and before the product is ready for packing; the estimated cost of producing the fiber, tow, or other I product; the percentage of fiber. and tow, if any, from a given weight of green leaves ; and, lastly, the simplicity, durability, and safety of the working parts. 2. Whether they consider any machine or process worthy of the whole bonus, and, if so, which one. 3. If they do not consider any machine or process worthy of the whole bonus, then whether they consider any machines or processes entitled to a part thereof, and, if so, which ones and how much. For the information of persons who are interested in the above announcement, but who have little or no knowledge in regard to New Zealand hemp (or, as it is often called, New Zealand flax), it may be pointed out that PhorwiuTO tenax is entirely different from any other hemp or flax-plant. The leaves from which the fiber has to be extracted are sword-shaped, and about four to nine feet long; they are moderately pliable, and of great tensile strength. The fiber is embedded in tough vegetable-matter containing a gum and a staining substance, and the greatest difficulty in the process of extraction is the removal of the vegetable refuse, gum, and dye without damaging or staining the fiber. Specimens of New Zealand hemp (Phor-toimto tenax) can be seen in many botanical gardens all over the world. It would be of little use to send samples of the leaves outside New Zealand, as when cut they soon wither and become stiff and brown, and altogether useless for treatment by any known process. Thomas M ac kenzie, .Minister of Agriculture. Department of Agriculture, Commerce, and Tourists, Wellington, New Zealand, September 22nd, 1911.
This article was originally published with the title "The Inventor's Department" in Scientific American 105, 26, 581-588 (December 1911)