Abstract: A viewfinder system for a single lens reflex camera where the field lens of the system is positionable in accordance with the distance of the objective lens exit pupil from the focal plane and eyepiece lenses are positionable in accordance with the field lens to maintain uniform viewfinder brightness without any essential change in image magnification.

Abstract: An instrument for tuning musical instruments where a low difference frequency is derived between the instrument to be tuned and a reference frequency. The difference frequency signal is shaped to a pulse train of constant amplitude and width pulses. The pulses are integrated with respect to time, and an indicating meter indicates when the instrument is precisely in tune or small sharp or flat deviations therefrom.

Abstract: A composition and method for reducing the loss of liquids by seepage through permeable ground surfaces is shown. The composition comprises an aqueous emulsion of asphalt including a cationic emulsifier, a nonionic surface active agent and elastomer solids. The compositions are particularly adapted for application to agricultural soils. After application to the ground surface, the surface is flooded with water to force the aqueous emulsion downward into the subsurface. A semi-permeable fluid barrier is created several inches below the surface. The composition and method are useful to create subsurface liquid barriers which permit the surface soil to be used for agricultural purposes.

Abstract: A drive system for a reciprocating blade saw wherein a motor rotates an eccentric which rocks a bell crank to reciprocate the saw blade, the eccentric and the bell crank being associated with masses which rotate and rock 180.degree. out of phase with the eccentric and bell crank and are so proportioned as to counterbalance those elements and minimize the vibration of the system. The counterbalancing masses are divided and mounted each side of the working elements so that no lateral torque forces are developed.

Abstract: An intrauterine device providing a membrane to cover substantially the entire surface of the uterine cavity, said device having a Y- or V-shaped resilient member with two diverging arms, a membrane covering the entire area between the diverging arms and, in addition, extending above an imaginary line passing through the terminal ends of the arms, and a flexible tail or string connected to the intersection of the arms for aiding in the removal of the device from the uterus when desired. The ends of the diverging arms have enlarged end portions and the arms are of unequal length so that the arms may be resiliently collapsed and placed in a tubular inserter with the enlarged end portions longitudinally spaced in the inserter.

Abstract: A solar heating system of the liquid heat transfer collector type in which provision is made for circulating the heat exchange medium only, then the collector temperature bears a predetermined relation to the storage medium, and where, a heat exchange liquid dissipating means is provided to dissipate heat in the medium when the collector temperature exceeds a predetermined value.

Abstract: A cable shaving tool for removing the outer covering of a cable at a point intermediate its ends, comprising a sectional shaving head adapted to be closed around the cable, a drive shaft operatively connected to the blade support in the shaving head, and remote means for driving the drive shaft and for adjusting and controlling the position of the shaving head elements to permit applying the shaving head to the cable and removing it therefrom; also the method of removing the outer covering of a cable.

Abstract: The disclosure describes a drive system including an engine with a rotor which has oscillatory motion. The engine may be of either an internal or external combustion type. The drive system further includes a conversion device coupled to the engine rotor and adapted to convert the oscillatory motion of the engine rotor to unidirectional energy. The power output of the system may be controlled by controlling the speed and length of stroke of the engine.

Abstract: A straight saw blade adapted for rapid reciprocation, the blade being tapered in cross-section across a substantial part of its width such that it is thinnest at or near the points of the teeth and substantially thicker throughout the portion adjacent to the back. The blade is stiff enough to be operated from one end, without tension.

Abstract: This specification discloses a method and construction for joining the ends of concrete reinforcing bars which permits the development of both tension and compression in the bars. A joining member compressively engages adaptor members integrally joined to the ends of the bars and reacts any forces tending to separate the bars, and further permits transmittal of compressive forces therebetween.

Abstract: A method of comminuting fresh algae which consists in carrying out a comminuting operation on said algae at a temperature lower than -20.degree.C. Preferably this temperature lies between the range -30.degree. to -100.degree. C. In carrying out the method it is advantageous for the fresh algae to be frozen at a temperature of less than -20.degree. C before being comminuted. In particular, after being broken down, the algae are comminuted by crushing into the form of a wet paste mix, the mean size of the particles in which is less than 10 micrometers.The invention also relates to apparatus for carrying out the comminuting operation which comprises a comminuting assembly and cooling means associated therewith to hold the operated temperature within said assembly at a level of -20.degree.C by means of a cooling agent. The invention furthermore extends to the algae product whenever produced by the method and apparatus aforementioned.

Abstract: Cell culture comprising a novel cell strain in suitable nutrient medium, wherein the novel cell strain is produced by disaggregated feline embryo tissue cell and serially passaging the same from about the 20th to about the 48th passage level, so as to be cultured and subcultured with the resultant cell strains remaining substantially diploid, typically fibroblastic and substantially free from morphological transformations. Subculturing is facilitated by treatment of a confluent sheet of the disaggregated cells chelating agent before each transfer into a new batch of nutrient medium.

Abstract: A surface bolt adapted to be mounted on an inner or outer surface of a closure member, such as a door or window, the bolt being slidable in guides between positions into and out of engagement with a keeper, the bolt having a recess extending across its outer surface, positioned and dimensioned to be engaged by one of the guides in the locking position of the bolt and to be resiliently and releasably held in such engaged position by a spring housed in the guide.

Abstract: This specification relates to apparatus and method for improving construction joints in reinforced concrete structures. A coupling member extends a short distance beyond the joint between two pours and has edges which mechanically couple to joining or adaptor members on the ends of reinforcing bars.

Abstract: A monitoring and control apparatus for an engine, particularly a water-cooled internal combustion marine engine, which includes devices for monitoring the temperature and/or flow of the coolant liquid and/or of the lubricant, the monitoring devices being included in an alarm system adapted to give visual and/or audible warning of an abnormal condition and to reduce automatically the speed of the engine, in order to prevent or minimize the danger of damage thereto.

Abstract: The invention relates to a process and an apparatus for cutting various materials and more specifically pieces of wood.The apparatus according to the invention, comprises a table and a pressure plate between which is held a piece of wood to be cut. The said table and the said plate are supported by a drum connected to a rotary driving device, equipped with radial forward movement devices. The cutting device also comprises a cutting tool installed in such a way that its knife acts on the piece of wood in accordance with a constant cutting radius.The process and apparatus of the invention are applicable to the cutting of various materials and more particularly pieces of wood, with a view to obtaining thin planar products, calibrated in thickness, of excellent quality and of perfect appearance.

Abstract: The process provided for the production of high-purity 1,3-bis-(.beta.-ethexyl)-5-amino-5-methyl-hexahydropyrimidine, also known as hexetidin, by reacting 1,3-bis-(.beta.-ethylhexyl)-5-nitro-5-methyl-hexahydropyrimidine with naphthalene-1,5-disulphonic acid in a solvent to selectively preciptitate the novel intermediate compound 1,3-bis-(.beta.-ethylhexyl)-5-nitro-5-methyl-hexahydropyrimidine-naphthale ne-1,5-disulphonate, which is separated off, treated with aqueous alkali to produce 1,3-bis-(.beta.-ethylhexyl)-5-nitro-5-methyl-hexahydropyrimidine, and subsequently hydrogenated to produce high-purity hexetidin.The invention relates to an industrially practicable process for the manufacture of high-purity 1,3-bis(.beta.-ethylhexyl)-5-amino-5-methyl-hexahydropyrimidine of the formula ##STR1## which is also known by the name of hexetidin and in view of its antimicrobial activity is used as an antiseptic and insecticide.From M.

Abstract: A soluble immunogenic extract of human blood lymphocytes, a non-toxic immunosuppressive antilymphocytic serum raised by the extract, a non-toxic immunosuppressive antilymphocytic immunoglobulin G derived from the serum, and methods of isolating the extract, raising the antiserum and isolating the immunoglobulin G.

Abstract: 1. A new and distinct variety of apple tree, substantially as herein shown and described, characterized particularly as to novelty by its possession of a unique combination of characteristics, including a laterally branched habit with straighter branches and less tendency to meander than usually found in apple trees, fruit having skin of a deep, rich red color and flesh of an attractive cream color, tender, fine-grained, juicy and having present therein pink flecks adding to usual attractiveness, said characteristics being prevalent essentially before maturity is attained.

Abstract: Bright, tarnish resistant and color stable ternary alloys of about 40 - 90% of tin, about 10 - 50% cobalt and about 1 - 28% of a third metal of Periodic Group II.sub.B, III.sub.B or VI.sub.B. Typical third metals are zinc, cadmium, indium, antimony or chromium. The alloys are electrodeposited from aqueous acidic baths at a temperature of about 50 - 85.degree. C and current density of about 5 - 45 A/ft.