Abstract: Generally trapezoidal web sections of non-uniform shape for fabricating structural I-section beams having varying bending modulus are sheared from a continuous roll of metal stock by a shear whose platen is oscillated, as a series of pieces are cut from a length of metal sheet or plate, about an axis perpendicular to the plane of the stock material. The platen angle is determined and controlled by a computer to which design criteria are fed.

Abstract: A razor including an inner tubular member formed with two opposite longitudinal slots of different length, a blade assembly fitted into the inner tubular member and including a first mounting element and a second mounting element engaged with the first mounting element, an intermediate tubular member enclosing the inner tubular member, an outer tubular member enclosing the intermediate tubular member and having at an inner bottom a protruded portion formed with a plurality of tenons adapted to engage the mortises of the inner tubular member, and a cap having an opening at a center and engageable with a top end of the intermediate tubular member, whereby the razor will be completely kept from dirt when not in use.

Abstract: A tool having a base plate for sliding along a roadway surface and defining slots extending rearwardly from a forward edge of the base plate. Each slot has parallel wall surfaces between which a flexible tab to be cut is received and held upright until a cutting edge, at the slot end, severs the tab at roadway surface level. Side walls and a rear wall on the base plate confine severed tabs on the base plate until tab discharge into a receptacle. Blade surfaces on the base plate are inclined downwardly and forwardly. A closure, on a modified form of the tool, may swing open to admit a tab being severed and thereafter close to prevent loss of severed tabs from the tool. A pivotally mounted handle facilitates sliding of the tool along a roadway in surface contact with same. A discharge opening in the rear wall of the modified tool facilitates tab discharge into a receptacle.

Abstract: A cutting type rescue tool having a body with an axis of actuation. A spacer on the body spaces a reaction arm, which reaction arm extends across the axis. An actuator barrel contains a piston from which a piston rod extends to a cutting blade that faces the reaction arm. The actuator barrel is slidably mounted in the body and is retained thereto. Braking shoulders on the actuator barrel and on the body oppose a decelerator device which reduces impact forces between the actuator barrel and the body, after the piston bottoms on the actuator barrel.

Abstract: A sighting apparatus for a bow is fixedly mounted on a bow and is provided with a lever such that a sight unit is tilted as the sighting device is adjusted for longer distances so as to compensate for gravity effect on arrows. The sighting apparatus comprises a gauge which is adjustably mounted to the sighting apparatus and may be locked into an adjusted position corresponding to an arrow having alternate flight characteristics from an arrow used to calibrate the apparatus.

Abstract: The device has a fixed rod 15 aligned with the working axis of the tool, e.g. a pistol drill. The rod 15 is in spring biassed, telescopic sliding engagement with a tube 16 fixed to an indicator head 17. The head 17 includes a universal-type pivotal coupling and bears indicia to indicate when the axis of the rod 15 is perpendicular to a work surface against which the head 17 bears. The rod 15 carries a depth gauge scale 19, and an adjustable stop 20 determines the maximum depth of penetration of the drill bit into the workpiece.

Abstract: A pipe alignment system and method is provided for positioning a pipe line along a predetermined path. A light transmitter generates a reference light beam along which the pipe line is to be positioned. The light beam has wavelengths substantially in the green portion of the optical spectrum. An optical target is positioned at one end of each pipe section to assist in alignment thereof. Preferably, the optical target has a green tint which filters the green light from ambient light. The optical target may also have reference indicia thereon to assist in aligning the target with the reference beam of light.

Abstract: A chalk line tool consists of a chalk dispensing compartment, a reel for string and a grinder that rotates with the reel. The chalk dispensing compartment accepts chalk sticks, which the grinder grinds into the chalk dust that coats the string. The grinder consists of a drum with integral grinding teeth. When the drum rotates in the direction that corresponds to the unwinding of the string from the reel, the grinding teeth grind the end of the chalk stick. The chalk tool is easily, quickly and neatly loaded by dropping the chalk stick into the chalk dispensing compartment.

Abstract: A lens shape measuring instrument includes a slide base plate in parallel with a chucking shaft of an eyeglass lens, a flat contactor arranged on a first measuring bar disposed on a first rotating shaft, and a V-shaped contactor disposed on a second measuring bar disposed on a second rotating shaft, so that the flat contactor and the V-shaped contactor can be brought into contact with the peripheral surface of the eyeglass lens at the same time. The thickness center of the peripheral surface of the eyeglass lens can be detected by detecting positional change of the slide base plate, and the thickness of the peripheral surface of the eyeglass lens can be detected by rotation difference between the first rotating shaft and the second rotating shaft corresponding to the positional change and from shape of the V-shaped contactor.

Abstract: A measuring system for measuring dimensions of an article such as a bottle has two opposed measuring heads each having a measuring probe, a contact identifying trigger operated by the probe, a base upon which the article to be measured stands, and first and second stepper motor assemblies. The stepper motor assemblies move the measuring heads horizontally and vertically. The base is angularly movable about an axis normal to the plane of the base so as to rotate an article standing on the base so that the different parts of the article are brought into a measuring plane defined as the plane in which the measuring heads move. The measuring probes then measure that part of the article lying in the measuring plane.

Abstract: A method and a gage for testing uncoupling tools to ensure proper operation prior to use. The uncoupling tool gage simulates the actual conditions under which the uncoupling tool is expected to perform. The gage has a cylindrical guide for slidably receiving a magnet housing. The guide is supported such that it is concentric with respect to the probe of an uncoupling tool to be checked. The magnet housing is placed inside the cylindrical guide and then moved toward the bottom thereof. When the magnet moves into proximity with a switch in the uncoupling tool probe, an indicator lamp in the uncoupling tool illuminates. If the face of the magnet housing is within a range band on the outside of the guide when the indicator is illuminated, then the uncoupling tool is operating properly.

Abstract: A metric and English measuring gauge including parallel first and second bar members having mutually engaging side faces and including contact end portions for engagement with tubular members wherein the offset of such tubular members will be indicated by the relative longitudinal position of the bar members. A shoulder retaining part is enclosed around the bar members and has windows on opposite sides for observing metric and English scales imprinted un opposite sides of the bar members for measuring wall thickness.

Abstract: A tool for installing siding on a building wall is disclosed wherein only two formed metal parts are shown which are of utter simplicity and are relatively adjustable one to the other to provide variation in desired exposure to weather of each underlying siding member as determined by the positioning of the parts in assembled relation. A generally J-shaped bracket and an adjustable U-shaped siding support are provided with the support being releasably attached to the bracket with a pair of legs on the support extending through a pair of a series of openings in the bracket. The bracket has a lower hook with a reversely bent lip which may be inserted into wedged engagement between a building wall and an affixed strip of siding for readily securing the tool in position to enable a leg of the support to provide the only assistance required for a single worker to install an overlying strip of siding.

Abstract: A magnetic point identifier to be used in the construction of structures wherein a hole is to be formed at a specific point in a surface of the structure, the identifier including a small magnetic element to be disposed to correspond the specific point, and including an indicator frame with a metallic, magnetically attractive pointer suspended therein. The indicator frame includes a base portion, an upstanding support member extending upwardly from the base portion, and a horizontal suspension arm which extends outwardly from the upstanding support member so as to overly the base portion which has a tapered free distal end to enable positioning of the indicator frame within a corner.

Abstract: An adjustable gage is provided with a plurality of pairs of depth stops along the jaws or arms which support the pointed anvils which contact an internal or external cylindrical surface. By adjusting selected depth stops, an either retracted or extended positions, one pair of depth stops engages a rim or abutment surface of a cylindrical member, thereby insuring that the measurement anvils will contact diametrically opposite sides of the cylindrical surface to be measured along a plane which is substantially normal to the axis of the cylindrical surface. This avoids oblique misalignments of the gage and assures precise measurements.

Abstract: A suction roll (1), in particular for a paper web dryer, comprising a perforated roll jacket (2), with at least one non-rotatable hollow shaft (3) which communicates with the interior of the suction roll via openings (7, 7') and at least one closing member (9) displaceable in the axial direction for separating off at least one peripheral region of the suction roll. The at least one, in particular disc-shaped dividing wall (5) is located in the suction roll interior and has at least one, preferably central opening (22). It can be of benefit when the dividing wall (5) corotates with the roll and/or when the at least one closing member (9) has the form of a hollow cylinder. Further, if the non-rotatable hollow shaft (3) is designed to be axially displaceable, it can be used to control the size of the opening (22) in the dividing wall (5).

Abstract: A dryer densifier includes a hopper for receiving wet, dry and/or flaky thermoplastic waste material. The hopper feeds an auger barrel which is heated and insulated whereby material passing therethrough may be dried and fused together with other material. The auger barrel and screw are configured to leave sufficient space therebetween whereby heated vapors may pass along the length of the auger and exit to the atmosphere at the discharge end, and whereby the heated vapor may be collected by a vapor collecting hood. The material is discharged from the auger onto a shaker screen table where the fused and unfused materials are separated by the vibrating screen conveyor of the table. The unfused material is returned to the receiving hopper for further densification and the fused material is conveyed to a granulator, whereupon the dried and densified material is granulated.

Abstract: A paper web in a paper machine including a yankee dryer is dried and the moisture profile thereof controlled by arraying a plurality of gas burners in a cross-machine direction within the hood of the yankee dryer to direct heat toward different incremental width portions of the paper web. The burners are independently controlled by a scanning moisture gauge.

Abstract: An inverted dryer group having a single-wire draw in a multi-cylinder dryer in a paper machine, including steam-heated drying cylinders arranged in a lower row and against which the drying wire of the cylinder group presses a web to be dried into direct contact. Reversing cylinders or rolls of the dryer group are arranged above gaps between the drying cylinders inside a loop of the drying wire. A support wire is placed in contact with the reversing cylinders or rolls over a turning sector of about 60.degree. to about 120.degree.. The support wire is guided by guide rolls arranged in gaps between the reversing cylinders as well as by other necessary rolls. The web is pressed against the drying wire on the turning sector by tension of the support wire.

Abstract: A strap system which includes a strap (such as an instep strap) and a buckle. The buckle is engageable with the strap such that the strap defines an adjustable strap loop. The buckle is configured so that the size of the strap loop may be adjusted so as to vary the snugness of the strap system to the foot.

Abstract: An integral sole for a shoe includes a base plate, a stabilizing plate, and a heel member. The base plate is made of a cushioning material and includes a lower surface having a footprint embossing which engages a walking surface providing traction and comfort for the user. The stabilizing plate is horizontally located about and surrounding the footprint embossing and is made of a material which is harder than the material of the base plate. The stabilizing plate also engages the walking surface and includes a bridge portion extending outwardly from a toe and ball portion of the footprint embossing to provide lateral stability for the sole. The heel member is located peripherally about a heel portion of the stabilizing plate. The heel member is made of a material which is harder than the material of the stabilizing plate to provide a firm heel stability for the shoe. Preferably, the toe portion of the footprint embossing includes five separate toe-print areas.

Abstract: Cleanliness insole for shoes comprising a first layer (10) positioned facing the foot and formed to promote the passage of perspiration from its upper to its lower surface, and a second rigid layer (20) whose upper surface is in contact with the lower surface of the first layer, the second layer delimiting cavities (23) which open onto the upper surface of the second layer. These cavities form a moisture-storage volume and are filled with an absorbent material (30). The moisture is thus stored by the absorbent material, thereby avoiding its transfer to the rest of the shoe and preventing the moisture from rising under the effect of foot pressure.

Abstract: This split vamp athletic shoe (10) includes separated upper and lower vamp sections (18, 22) which are independently adjustable and provide the shoe with a hinge zone providing the shoe with flexibility. The shoe also includes an outsole (14) and a midsole (16), the outsole being unitarily formed to include upwardly extending instep support portions (36) which are attached to the upper vamp and extend substantially to the leading edge of the upper vamp to stiffen the shoe particularly in the instep area and provide stabilizing restraint against lateral motion and enhance the hinge action. The outsole also includes a second set of upwardly extending side support portions (38) which are spaced from said instep side support portions. In a second embodiment the midsole (116) includes unitarily formed side portions (166) recessed to receive the outsole side portions (136) and cooperating with said side portions to provide additional lateral stabilization and further enhancing the hinge action.

Abstract: A roof rake includes a generally planar snow moving surface and a handle assembly for manipulating the snow moving surface on the roof. The handle assembly may be gripped by a user who is not located on the roof to pull the snow moving surface from a position on the interior of the roof towards the eaves of the roof to remove a swath of snow. To prevent damage to the roof during this snow removal operation, the lower edge of the snow moving surface is spaced above the surface of the roof by a plurality of rotatable wheels carried on the snow moving surface. One wheel is adjacent each side of the snow moving surface. A plurality of plastic tabs are carried on the lower edge of the snow moving surface. If one of the wheels falls off an edge of the roof, one or more of the plastic tabs will engage the roof to keep the lower edge of the snow moving surface spaced above the surface of the roof.

Abstract: In a machine for digging a trench, in which the digging apparatus comprises an elongated boom having a movable chain around its periphery and which is lowered into the ground, the problem of dislodged boulders which heretofore would be excavated into the machine where they often damaged the conveyor belt system or became stuck, is prevented by an elongate bar or drum which is attached to the frame of the machine in close proximity to the operating chain and immediately before the boulder would otherwise enter the machine. The boulder is held there until it either breaks apart or its abraded by further action of the chain to a sufficiently small size that it can safely navigate through the machine and be expelled in the normal course.

Abstract: Implement assemblies have previously used mechanically attached adapters that are secured to the base edge by bolts and/or other wedging type mechanisms. In these known implement assemblies, the wedge member has a tendency, during use, to become loose and fall out which allows the adapter to fall off of the base edge. In the subject arrangement, a clamp member is disposed in a longitudinally extending opening of an upper strap of an adapter and a wedge member is forcibly driven into the assembly such that the wedge member is disposed between the clamp member and the adapter to effectively secure the upper strap in intimate engagement with a mounting portion of an implement. At the same time, a resilient pad member is disposed between the adapter and the wedge member which effectively biases the adapter into intimate contact with the mounting portion of the implement.

Abstract: In the process of soil excavating work or like work with the use of excavators and loaders, it is becoming more usual to use different hydraulically functioning implements. It is often necessary to exchange these implements several times during a working day, necessitating the driver to connect and disconnect the hydraulic hoses involved manually, which can be a time-consuming task and one which is encumbered with the risk of oil spilling from the hoses and generally soiling the clothing of the workman involved, tools and the surrounding ground.

Abstract: This invention relates to a variably decorative picture frame having semi-cylindrical about the face thereof wherein are disposed cylindrical tubes adapted to have therein decorative material in harmony with the decor or environment in which the frame is placed, the same being readily changeable as may be desired or required.

Abstract: An illuminated advertising media display assembly comprising an elongated group of viewing modules through which to display advertising indicia. An elongated, translucent banner is adapted to be horizontally scrolled between a pair of drive rollers. The banner includes a plurality of receiving enclosures adapted to compactly store translucent advertising media. Each module is bounded by a pair of idler rollers for orienting the banner and advertising media into position with respect to the viewing aperture. A pair of modules are pivotable with respect to the supporting assembly to provide access to the interior of the enclosure formed by the modules and for changing the visual orientation of a viewing aperture relative to an adjacent module. When the drive rollers are rotated, the banner will be dynamically scrolled from one to the other, each advertisement being sequentially visible at the adjacent viewing apertures.

Abstract: A valance assembly designed for attachment to existing, in-store display fixtures is disclosed. The valance assembly is completely assembled prior to in-store delivery, and requires only the unfolding of hinged mounting brackets for installation. The valance assembly is intended to carry graphics displays or headers such as advertisements or merchandise promotional information.

Abstract: A safety catch in particular for underwater guns or the like, comprises movable means for locking the travel of a trigger for activation of means of firing a projectile element. In oder to avoid direct, visual checking of the condition of the safety catch, according to the invention the safety catch is provided with means for indicating the condition of activation thereof, which in the position of locking the travel of the trigger are disposed such that they can be felt directly by the hand or finger which controls activation of the trigger, in the normal position For grasping the grip of the gun and/or the trigger.

Abstract: A sporting or hunting arm comprising a barrel assembly, a casing containing the triggering mechanism, a safety means for changing the arm from a safe to a ready-to-fire position, and a supplementary safety device comprising a time-lag relay started by a sensor when the safety lever is changed into the ready-to-fire position and emitting a signal after lapse of a preadjusted time interval, the signal being either an audible signal emitted by a buzzer or a visible signal emitted by a diode, and/or causing an actuator to return the safety means into the safe position. The safety means can be a cocking slide held in cocked position by a holding lever, wherein the actuator acts on the holding lever or on a shock-safety means. Warning means responding to the state of loading of the battery and an adjusting device accessible from outside can be provided.

Abstract: The present invention presents a locking assembly which may be installed in a firearm during manufacture or as a retrofit to an existing firearm and which locks the bolt of the firearm against normal movement in the receiver. The assembly includes a cylinder lock installed in the stock of the firearm below the receiver and which has a locking element which is extendable through an aperture in the receiver to engage a blind aperture provided in the bolt. In this manner the assembly locks the bolt in a position which prevents loading and firing of the weapon and which also prevents its disassembly until the lock is released. The locking assembly may also be provided in kit form for retrofitting particular makes and models of firearms wherein the kit includes the lock assembly, a replacement receiver, a replacement bolt and a template for locating the position on the stock in which to install the lock assembly.

Abstract: A gun grip assembly including two body panels to be received at the opposite sides of a gun handle, and two outer grip panels to be received at the outer sides of the two body panels respectively and preferably forming side portions of a grip unit having a connecting portion extending between and interconnecting the two side portions. The side portions of the grip unit are attached to the two body panels respectively, and the body panels contain openings at locations offset from/the side portions of the grip unit to receive threaded fasteners which extend through the body panels but not through the side portions of the grip unit and which tighten the body panels against the opposite sides of the handle.

Abstract: A cartridge for dispensing an animal attracting scent. The inventive device includes a plurality of scent cartridges stored within a container sealed by a cap. The cap includes a depending hook extending from an interior of the cap for extracting an individual scent cartridge from the container to eliminate contact of the user with the scent cartridge to preclude contamination thereof.

Abstract: This invention relates to fishing gear in the form of a minnow caddy. The minnow caddy has a main caddy body which is opaque (black) and forms a hiding place for a minnow or like bait fish into which the bait fish will swim when the minnow caddy is placed in a bait receptacle. The main caddy body having an entrance end and an exit end is carried by a control handle which permits the positioning of the main caddy body within the bait receptacle. At the exit end of the main caddy body there is an exit opening in which there is positioned a hooking aperture body having a monoleaf spring gate with opposed monoleaf springs.

Abstract: A fishing lure of resilient material which when retrieved from the water successfully duplicates the natural swimming motion of an eel or a snake such that the head and the tail of the lure moves back and forth along the longitudinal axis of the lure. The lure has an elongated head portion with ridges, a mid-body portion with a U-shaped configuration, and an enlarged tail portion. The lure is characterized by a predetermined resilience, and along with its U-shaped configuration, causes undulating motion of the head and tail portions. As the lure is retrieved from the water, the water forces cause the lure to reach toward a linear configuration until the lure resiliency has reached a maximum, whereupon, the lure reverts to its U-shaped configuration and so on. An alternative embodiment of the lure characterizes a lizard.

Abstract: The present invention discloses a method of producing light sensitive fishing lures and fishing lures which are capable of reversibly changing color with changing exposure to a light source. In one embodiment, a photochromatic material is incorporated into the mold to form a flexible bodied fishing lure. In another embodiment, the photochromatic material is mixed with a bonding agent forming a spray or dip in which a rigid bodied fishing lure is coated. In both cases, the fishing lure has an original, first color which reversibly changes to a second color with exposure to light, and thereafter gradually changes back to the original, first color in the absence of light such as when traveling under water.

Abstract: A robot system for exterminating termites living in wood structural members under the floor of an architectural structure. The robot system comprises a robot including an onboard computer which is electrically connected through radio communication with a host computer located outside the robot. The robot includes a main body and is equipped with a locomotive mechanism including a pair of caterpillars located on the opposite sides of the main body. The caterpillars are driven by driving motors mounted on the robot and can be independently operated. The robot includes a mechanism for controlling the vertical positions of various sections of the main body relative to the caterpillars. A nozzle mechanism for spraying chemical or insecticide and a CCD camera are mounted on the main body. The onboard computer and host computer are operatively associated with each other to control the driving motors, the vertical position controlling mechanism, the nozzle mechanism and the CCD camera.

Abstract: High-strength ring for protecting the trunk of a tree from contact with lawn maintenance equipment, and other hazards, said ring being characterized by a high-strength stabilizing locking mechanism and a rolled upper edge.

Abstract: A landscaping border is provided which is attractive, safe for animals and children to play around and less susceptible to biological growth. Provided is a landscaping border comprising: a tubular polyethylene mesh with a mesh size of at least about 0.25 inches and no more than about 3 inches and a diameter of at least about 3 inches and no more than about 10 inches; biodegradable ground cover, preferably pine straw, wherein at least 95% of the weight of the biodegradable ground cover is contained within the mesh and no more than about 5% of the total weight of the biodegradable ground cover protrudes through said mesh. The inventive border also preferably comprises a biocide.

Abstract: A cabinet has overlapping doors to cover a cabinet opening. The overlapping doors include sealing gaskets formed on interior surfaces of the doors. The doors are shaped for the gaskets of the doors to overlap and abut in sealing engagement upon closure of the doors.

Abstract: Outdoor or indoor stand for supporting decorative trees, such as Christmas trees. In this stand, the bottom of a tree trunk is inserted into a cylindrical support vessel medially and orthogonally mounted on the top surface of a base plate. The lower and upper portions of the tree trunk are held by first and second abutment portions. Each of the first and second abutment portions and a support arm portion comprises three members that are separately produced but assembled into and handled in a unit. The stand prevents possible sway of the tree such as due to outside impact, firmly supports any thickness of tree trunk and achieves easiness to handle.

Abstract: A method of using a paper packing product (10) to store/ship a plant (12) with exposed roots (14). The method comprises the steps of: providing a multitude of narrow, elongated strips of paper material; wetting the paper strips; and packing the paper strips around the exposed roots (14) of a plant (12). In this manner, a root-packed plant is created which comprises a plant with unsoiled roots and a paper packing product packed around the unsoiled roots. Preferably, the paper strips include a plurality of transverse folds against the natural resilience of the material to form a longitudinally compressed strip and these strips are intertwined and interconnected to form a resilient mass. The preferred paper material is untreated thirty pound kraft paper and the strips are approximately 1/8 inch wide and approximately four to six inches long in an unfolded state.

Abstract: A vehicle door upper assembly is provided for removable mounting on a vehicle door lower assembly, and comprises a body subassembly, a window subassembly and a connecting subassembly. The body subassembly includes outer and inner panels interconnected by a panel spacer and includes a window opening bounded by a window pocket. The window subassembly includes a track mounted within the window pocket and outer and inner windowpanes slidably received in the window pocket. The connecting subassembly includes a structural rod mounting L-shaped pins with legs depending downwardly from the body subassembly and removably received in pin receivers or stake pockets formed in the vehicle door lower assembly.

Abstract: A seal for precluding an entrance of rodents or debris underneath a door. The inventive device includes a mounting assembly securable to a lower edge of a door, such as a security door or the like. A flexible seal is supported by the mounting means so as to extend downwardly from the lower edge of the door to contact a ground surface therebeneath. The flexible seal projects laterally of the mounting assembly so as to additionally contact adjacent lateral surfaces of the associated structure. The device allows an entrance door of the structure to be left open with only the security door closed to permit a passage of air currents through the security door while simultaneously precluding an entrance of rodents or debris underneath the security door.

Abstract: An interlocking joint or fastening means is provided wherein one fastening member is provided integral to a panel member to be fastened to another panel member. A second fastening member is provided having a tongue that intrudes into an opening provided by the integral fastening member.

Abstract: A flooring system is provided for elevating flooring panels above a subfloor, such as the subfloor of a computer room. The invention provides a flooring substructure which has a plurality of elongated tracks arranged parallel to one another. A plurality of brackets are securable against the tracks, and a plurality of channel members are secured to the brackets so that the channels are aligned perpendicularly to the tracks. The channels are configured for supporting the flooring panels. Adjustable leveling screws are threaded upwardly through the brackets to contact the subfloor and support the substructure.

Abstract: A soil anchor and a method of installing a soil anchor, the soil anchor having: an expandable anchor body; a device for piercing and parting soil at the front end of the soil anchor; a device for transmitting force from a location remote from the soil anchor to the anchor body; a device for transporting hardenable material from a location remote from the soil anchor into the expandable anchor body to wedge the anchor body into the soil; and a device for leading at least one cable to avoid contact between at least one cable and the hardenable material, and for permitting movement of at least one cable adjacent the anchor body while the hardenable material is hardening or hardened.

Abstract: A system for containment of heavy vapor cloud and aerosol from a potential source of hazardous vapor comprising walled surfaces surrounding the vapor source and a roof above the vapor source and forming with the walled surfaces an enclosure for the vapor source. The roof is porous with openings therethrough dimensioned for minimizing wind shear and extending over at least about 20% of the surface area of the roof, and a device is located within the enclosure for absorbing the vapor.