Insecticides & Fungicides/Spreader-stickers, Wetting Agents: Getting the most out of Your SpraysWritten by Thomas Ogren
Spreader-stickers, Wetting Agents: Getting most out of Your Sprays
Spreader-stickers or if you prefer, sticker-spreaders, are agents we can add to garden sprays to make them more effective. These additives are commonly used in commercial horticulture and in agriculture, but for some reason are as yet relatively unknown to most gardeners. Sticker-spreaders can be made of many different components, organic or inorganic. Often actual ingredients in a particular brand of sticker-spreader will be kept secret, as a proprietary formulation known only within company producing it. Some brands use silicone-based surfactants, oils, emulsifiers and buffering agents, while others may use odd combinations of things like fish oil and fatty acid soaps. Several are made entirely from some sort of emulsified soybean oil. Actually, common dish soap will act as a sticker-spreader, it just won’t be as effective. To be totally technically correct here, sticker-spreader is a combination of two adjuvants. Adjuvants are materials added to spray mixtures to increase effectiveness of main active ingredient. If we want to be completely correct with our terminology here, we probably ought to note too that spreaders are adjuvant surfactants. Surfactants are adjuvants that reduce surface tensions of solutions, helping them spread and cover leaves more effectively. Stickers are adjuvants that aid in attachment to a surface. The water-soluble wax product often used to spray Christmas trees to keep them turgid, Wiltpruff, is also sometimes used as a sticker-spreader. I recently did some comparison spraying of roses in my own garden. I was spraying roses with a homemade combination to keep darn deer from eating them into ground. With both batches of spray I used, per gallon of water, two raw eggs, four cloves of garlic, and a cup of skim milk. I blended all ingredients in a blender before putting them in sprayer. I sprayed two different sections of roses. In first section I used above mix, with addition of 6 tablespoons of dish soap. In second section of roses I used same mix but used two tablespoons of a commercial grade sticker-spreader.
Can your sundial really tell the time?Written by Hugh Harris-Evans
"I am a sundial, and I make a botch Of what is done far better by a watch"
So wrote Hilaire Belloc, but is this really fair? Sundials are earliest known form of time-keeping having been used for some five thousand years. The Greek historian Herodotus stated that sundials were first used by Chaldeans and Sumerians in Babylonia which was part of modern Iraq. They used vertical rods on their buildings and noted position of shadow to record passing of hours. The concept was developed by Greeks and Romans who constructed various different shapes of dial to enable them to tell time and season of year. Usually these were bowl-shaped dials with vertical or horizontal gnomons (shadow-casters) and hour lines marked in hollow of bowl. Over years more elaborate designs were produced until advent of accurate clocks when function of sundial became more decorative than as a reliable means of telling time.
The question is often asked "Can a sundial really tell correct time?" to which you will receive Alice in Wonderland reply that it depends upon what you mean by "the correct time". Our clocks and watches work on basis of there being exactly twenty-four hours between one day and next but, because of eliptical nature of earth's orbit around sun, time shown on sundial will vary according to seasons. In February by clock sun is almost fifteen minutes slow, whereas during spring and summer months it gains and loses between four and six minutes in two cycles. At other extreme in November sundial appears to be some seventeen minutes fast. In fact sundial is accurate on only four days of year, about April 15, June 14, September 2 and December 25. Some sundials include a table showing deviation from "clock time" according to date.
The time indicated by sun will also vary with location of dial. The sun travels across sky at rate of fifteen degrees per hour so every degree of longditude represents a difference of four minutes from standard meridian for region. The angle of gnomon also depends on situation, so to set up your sundial correctly you need to know both latitude and longditude of its location. For United States and United Kingdom this site can provide information. The gnomon should be set at angle in degrees which is equal to latitude of your location. The sundial can then be fixed with gnomon pointing to Pole Star. There are various ways of achieving this, easiest of which, is to use a compass adjusted for magnetic variation. Further details are beyond scope of this article, but for those interested look at this site. If you have read this far you will have discovered that there is a great deal more to sundial than a mere item of garden decoration. If this has piqued your interest in subject, then you are not alone. There are Sundial Societies in countries around world. The North American Sundial Society has details of its objects and activities on its website.