A hardiness zone is a geographic area defined to encompass a certain range of climatic conditions relevant to plant growth and survival. The original and most widely-used system, developed by the United States Department of Agriculture as a rough guide for landscaping and gardening, defines 13 zones by annual extreme minimum temperature, it has been adapted to other countries in various forms. Unless otherwise specified, "hardiness zone" or "zone" refers to the USDA scale. For example, a plant may be described as "hardy to zone 10": this means that the plant can withstand a minimum temperature of -1 °C to 3.9 °C. Other hardiness rating schemes have been developed as well, such as the UK Royal Horticultural Society and US Sunset Western Garden Book systems; the USDA system was developed to aid gardeners and landscapers in the United States. State-by-state maps, along with an electronic system that allows finding the zone for a particular zip code, can be found at the USDA Agricultural Research Service website.
In the United States, most of the warmer zones are located in the deep southern half of the country and on the southern coastal margins. Higher zones can be found in Puerto Rico; the middle portion of the mainland and central and northern coastal areas are in the middle zones. The far northern portion on the central interior of the mainland have some of the coldest zones and have much less consistent range of temperatures in winter due to being more continental, thus the zone map has its limitations in these areas. Lower zones can be found in Alaska; the low latitude and stable weather in Florida, the Gulf Coast, southern Arizona and California, are responsible for the few episodes of severe cold relative to normal in those areas. The Pacific Ocean keeps the Pacific Northwest in warmer zones than nearby inland areas; the warmest zone in the 48 contiguous states is the Florida Keys and the coldest is in north-central Minnesota. The first attempts to create a geographical hardiness zone system were undertaken by two researchers at the Arnold Arboretum in Boston: the first was published in 1927 by Alfred Rehder, the second by Donald Wyman in 1938.
The Arnold map was subsequently updated in 1951, 1967, 1971, but fell out of use completely. The modern USDA system began at the US National Arboretum in Washington; the first map was issued in 1960, revised in 1965. It used uniform 10 degree Fahrenheit ranges, became widespread among American gardeners; the USDA map was revised and reissued in 1990 with freshly available climate data, this time with 5-degree distinctions dividing each zone into new "a" and "b" subdivisions. In 2003, the American Horticultural Society produced a draft revised map, using temperature data collected from July 1986 to March 2002; the 2003 map placed many areas a half-zone higher than the USDA's 1990 map. Reviewers noted the map zones appeared to be closer to the original USDA 1960 map in its overall zone delineations, their map purported to show finer detail, for example, reflecting urban heat islands by showing the downtown areas of several cities as a full zone warmer than outlying areas. The map excluded the detailed a/b half-zones introduced in the USDA's 1990 map, an omission criticized by horticulturists and gardeners due to the coarseness of the resulting map.
The USDA rejected the AHS 2003 draft map and created its own map in an interactive computer format, that the American Horticultural Society now uses. In 2006, the Arbor Day Foundation released an update of U. S. hardiness zones, using the same data as the AHS. It revised hardiness zones, reflecting warmer recent temperatures in many parts of the country, appeared similar to the AHS 2003 draft; the Foundation did away with the more detailed a/b half-zone delineations. In 2012 the USDA updated their plant hardiness map based on 1976–2005 weather data, using a longer period of data to smooth out year-to-year weather fluctuations. Two new zones were added to better define and improve information sharing on tropical and semitropical plants, they appear on the maps of Hawaii and Puerto Rico; the map has a higher resolution than previous ones, is able to show local variations due to things such as elevation or large bodies of water. Many zone boundaries were changed as a result of the more recent data, as well as new mapping methods and additional information gathered.
Many areas were a half zone warmer than the previous 1990 map. The 2012 map was created digitally for the internet, includes a ZIP Code zone finder and an interactive map; the USDA plant hardiness zones for selected U. S. cities as based on the 2012 map are the following: As the USDA system is based on average annual extreme minimum temperature in an area, it is limited in its ability to describe the climatic conditions a gardener may have to account for in a particular area: there are many other factors that determine whether or not a given plant can survive in a given zone. Zone information alone is not adequate for predicting winter survival, since factors such as frost dates and frequency of snow cover can vary between regions; the extreme minimum itself may not be useful when comparing regions in different climate zones. As an extreme example, most of the United Kingdom is in zones 8-9, while in the US, zones 8-9 include regions such as the subtropical coastal areas of the southeastern US and Mojave and Chihuahuan inland deserts, thus an American gardener in such an area
1940 United States Census
The Sixteenth United States Census, conducted by the Census Bureau, determined the resident population of the United States to be 132,164,569, an increase of 7.3 percent over the 1930 population of 123,202,624 people. The census date of record was April 1, 1940. A number of new questions were asked including where people were 5 years before, highest educational grade achieved, information about wages; this census introduced sampling techniques. Other innovations included a field test of the census in 1939; this was the first census in which every state had a population greater than 100,000. The 1940 census collected the following information: In addition, a sample of individuals were asked additional questions covering age at first marriage and other topics. Full documentation on the 1940 census, including census forms and a procedural history, is available from the Integrated Public Use Microdata Series. Following completion of the census, the original enumeration sheets were microfilmed; as required by Title 13 of the U.
S. Code, access to identifiable information from census records was restricted for 72 years. Non-personally identifiable information Microdata from the 1940 census is available through the Integrated Public Use Microdata Series. Aggregate data for small areas, together with electronic boundary files, can be downloaded from the National Historical Geographic Information System. On April 2, 2012—72 years after the census was taken—microfilmed images of the 1940 census enumeration sheets were released to the public by the National Archives and Records Administration; the records are indexed only by enumeration district upon initial release. Official 1940 census website 1940 Census Records from the U. S. National Archives and Records Administration 1940 Federal Population Census Videos, training videos for enumerators at the U. S. National Archives Selected Historical Decennial Census Population and Housing Counts from the U. S. Census Bureau Snow, Michael S. "Why the huge interest in the 1940 Census?"
CNN. Monday April 9, 2012. 1941 U. S Census Report Contains 1940 Census results 1940 Census Questions Hosted at CensusFinder.com
Pennsylvania the Commonwealth of Pennsylvania, is a state located in the northeastern and Mid-Atlantic regions of the United States. The Appalachian Mountains run through its middle; the Commonwealth is bordered by Delaware to the southeast, Maryland to the south, West Virginia to the southwest, Ohio to the west, Lake Erie and the Canadian province of Ontario to the northwest, New York to the north, New Jersey to the east. Pennsylvania is the 33rd-largest state by area, the 6th-most populous state according to the most recent official U. S. Census count in 2010, it is the 9th-most densely populated of the 50 states. Pennsylvania's two most populous cities are Philadelphia, Pittsburgh; the state capital and its 10th largest city is Harrisburg. Pennsylvania has 140 miles of waterfront along the Delaware Estuary; the state is one of the 13 original founding states of the United States. Part of Pennsylvania, together with the present State of Delaware, had earlier been organized as the Colony of New Sweden.
It was the second state to ratify the United States Constitution, on December 12, 1787. Independence Hall, where the United States Declaration of Independence and United States Constitution were drafted, is located in the state's largest city of Philadelphia. During the American Civil War, the Battle of Gettysburg was fought in the south central region of the state. Valley Forge near Philadelphia was General Washington's headquarters during the bitter winter of 1777–78. Pennsylvania is 170 miles north to south and 283 miles east to west. Of a total 46,055 square miles, 44,817 square miles are land, 490 square miles are inland waters, 749 square miles are waters in Lake Erie, it is the 33rd-largest state in the United States. Pennsylvania has 51 miles of coastline along Lake Erie and 57 miles of shoreline along the Delaware Estuary. Of the original Thirteen Colonies, Pennsylvania is the only state that does not border the Atlantic Ocean; the boundaries of the state are the Mason–Dixon line to the south, the Twelve-Mile Circle on the Pennsylvania-Delaware border, the Delaware River to the east, 80° 31' W to the west and the 42° N to the north, with the exception of a short segment on the western end, where a triangle extends north to Lake Erie.
Cities include Philadelphia, Reading and Lancaster in the southeast, Pittsburgh in the southwest, the tri-cities of Allentown and Easton in the central east. The northeast includes the former anthracite coal mining cities of Scranton, Wilkes-Barre and Hazleton. Erie is located in the northwest. State College serves the central region while Williamsport serves the commonwealth's north-central region as does Chambersburg the south-central region, with York and the state capital Harrisburg on the Susquehanna River in the east-central region of the Commonwealth and Altoona and Johnstown in the west-central region; the state has five geographical regions, namely the Allegheny Plateau and Valley, Atlantic Coastal Plain and the Erie Plain. New York Ontario Maryland Delaware West Virginia New Jersey Ohio Pennsylvania's diverse topography produces a variety of climates, though the entire state experiences cold winters and humid summers. Straddling two major zones, the majority of the state, with the exception of the southeastern corner, has a humid continental climate.
The southern portion of the state has a humid subtropical climate. The largest city, has some characteristics of the humid subtropical climate that covers much of Delaware and Maryland to the south. Summers are hot and humid. Moving toward the mountainous interior of the state, the winter climate becomes colder, the number of cloudy days increases, snowfall amounts are greater. Western areas of the state locations near Lake Erie, can receive over 100 inches of snowfall annually, the entire state receives plentiful precipitation throughout the year; the state may be subject to severe weather from spring through summer into fall. Tornadoes occur annually in the state, sometimes in large numbers, such as 30 recorded tornadoes in 2011; as of 1600, the tribes living in Pennsylvania were the Algonquian Lenape, the Iroquoian Susquehannock & Petun and the Siouan Monongahela Culture, who may have been the same as a little known tribe called the Calicua, or Cali. Other tribes who entered the region during the colonial era were the Trockwae, Saponi, Nanticoke, Conoy Piscataway, Iroquois Confederacy—possibly among others.
Other tribes, like the Erie, may have once held some land in Pennsylvania, but no longer did so by the year 1600. Both the Dutch and the English claimed both sides of the Delaware River as part of their colonial lands in America; the Dutch were the first to take possession. By June 3, 1631, the Dutch had begun settling the Delmarva Peninsula by establishing the Zwaanendael Colony on the site of present-day Lewes, Delaware. In 1638, Sweden established the New Sweden Colony, in the region of Fort Christina, on the site of present-day Wilmington, Delaware. New Sweden claimed and, for the most part, controlled the lower Delaware River region (parts of present-day Delaware, New Jersey, Pe
Pennsylvania Route 152
Pennsylvania Route 152 is a 25.3-mile-long state highway located in the U. S. state of Pennsylvania. The route travels north–south from an interchange with PA 309 located in the Cedarbrook neighborhood of Cheltenham Township in Montgomery County north to another interchange with PA 309 located northeast of Telford in Bucks County. PA 152 is known as Limekiln Pike for most of its length. From the southern terminus, the route passes through suburban areas to the north of Philadelphia, serving Dresher, Maple Glen, Chalfont. North of Chalfont, PA 152 runs through rural suburbs of Philadelphia before reaching Silverdale. Past here, the road continues northwest through Perkasie, where it turns southwest and passes through Sellersville before reaching its northern terminus. What is now PA 152 was Limekiln Road, a road built to transport lime from area kilns; the road was a turnpike between the 1850s and 1917. The route was first designated in 1928 to run from U. S. Route 611 in North Philadelphia to PA 113 in Silverdale.
PA 152 was extended north to US 309 in Sellersville in 1946, replacing the former routing of PA 413 between Perkasie and Sellersville. By 1960, the southern terminus of the route was cut back to its current location. PA 152 was extended west to end at PA 309 near Telford by 1970. PA 152 begins at an interchange with the Fort Washington Expressway in the community of Cedarbrook, located in Cheltenham Township, Montgomery County about 3,000 feet north of the Philadelphia city line. From this interchange, the route proceeds northeast on four-lane divided Easton Road, passing to the east of Arcadia University and to the northwest of Cheltenham High School. PA 152 turns north onto Limekiln Pike and crosses PA 73, running through residential and business areas in Glenside as a three-lane road with a center left-turn lane before losing the turn lane as it passes through the community of Edge Hill; the route curves northeast and comes to a bridge over SEPTA's Lansdale/Doylestown Line, where it enters Abington Township.
After the bridge, PA 152 turns northwest to remain along Limekiln Pike, making a curve back to the north a short distance later. The road continues north into Upper Dublin Township. PA 152 passes through a golf course before reaching an intersection with Jenkintown Road and Fitzwatertown Road in the community of Fitzwatertown, where it turns northwest. PA 152 heads north through areas of homes with some businesses before curving northeast and coming to an intersection with Susquehanna Road. Here, the route turns northwest and crosses under Norfolk Southern's Morrisville Line and the Pennsylvania Turnpike as a three-lane road with one northbound lane and two southbound lanes. After the Pennsylvania Turnpike bridge, Susquehanna Road splits to the northwest and PA 152 continues north along Limekiln Pike, passing businesses in Dresher; the road becomes two lanes again and continues northwest through residential neighborhoods, running through Jarrettown. PA 152 curves to the north and reaches the community of Maple Glen, where it crosses Norristown Road and PA 63.
At the intersection with the latter, PA 152 enters Horsham Township and continues to an intersection with Butler Pike. Farther north, the route crosses the Power Line Trail. In the community of Prospectville, the road comes to an intersection with PA 463. Past this intersection, the route continues north between a cemetery to the west and a golf course to the east before heading through a mix of farmland and homes. PA 152 intersects Lower State Road and turns northeast, running along the border between Montgomery Township to the northwest and Horsham Township to the southeast and crossing the Little Neshaminy Creek. PA 152 turns north and enters Montgomery Township, in the North Penn Valley region, coming to an intersection with County Line Road in the community of Eureka. Here, the route turns northwest to follow County Line Road. Past County Line Road, PA 152 continues north along Limekiln Pike, leaving the North Penn Valley region and entering Warrington Township in Bucks County; the route comes to an intersection with US 202 and the US 202 Parkway Trail before it curves to the northwest.
After crossing Upper State Road, PA 152 continues north past homes. PA 152 enters the borough of Chalfont; the route intersects US 202 Bus. and turns northeast to form a concurrency with that route on Butler Avenue, crossing the West Branch of Neshaminy Creek and heading into a business district. PA 152 splits from US 202 Bus. by turning northwest onto Main Street. The road passes homes and commercial development, coming to a bridge over SEPTA's Lansdale/Doylestown Line east of the Chalfont station. PA 152 curves north before it runs along the border between New Britain Township to the west and Chalfont to the east. PA 152 enters New Britain Township and becomes Limekiln Pike again, heading into a mix of agricultural and wooded areas with some homes and passing through the community of Newville; the road curves continues into Hilltown Township. At the intersection with Hilltown Pike, PA 152 turns northeast to remain along Limekiln Pike before turning northwest in the community of Hilltown. Following this, the route heads through the community of Mount Pleasant.
Farther northwest, the road enters the borough of Silverdale and becomes Baringer Avenue, passing homes and coming to an intersection with PA 113. At this point, PA 152 turns southwest to form a wrong-way concurrency with PA 113 on Main Street before splitting from that route by turning northwest onto Walnut Street; the route leaves Silverdale for Hilltown Township again and runs through areas of residenti
Wind-chill or windchill is the lowering of body temperature due to the passing-flow of lower-temperature air. Wind chill numbers are always lower than the air temperature for values; when the apparent temperature is higher than the air temperature, the heat index is used instead. A surface loses heat through conduction, evaporation and radiation; the rate of convection depends on both the difference in temperature between the surface and the fluid surrounding it and the velocity of that fluid with respect to the surface. As convection from a warm surface heats the air around it, an insulating boundary layer of warm air forms against the surface. Moving air disrupts this boundary layer, or epiclimate, allowing for cooler air to replace the warm air against the surface; the faster the wind speed, the more the surface cools. Many formulas exist for wind chill because, unlike temperature, wind chill has no universally agreed upon standard definition or measurement. All the formulas attempt to qualitatively predict the effect of wind on the temperature humans perceive.
Weather services in different countries use standards unique to their region. S. and Canadian weather services use. That model has evolved over time; the first wind chill formulas and tables were developed by Paul Allman Siple and Charles F. Passel working in the Antarctic before the Second World War, were made available by the National Weather Service by the 1970s, they were based on the cooling rate of a small plastic bottle as its contents turned to ice while suspended in the wind on the expedition hut roof, at the same level as the anemometer. The so-called Windchill Index provided a pretty good indication of the severity of the weather. In the 1960s, wind chill began to be reported as a wind chill equivalent temperature, theoretically less useful; the author of this change is unknown, but it was not Siple or Passel as is believed. At first, it was defined as the temperature at which the windchill index would be the same in the complete absence of wind; this led to equivalent temperatures. Charles Eagan realized that people are still and that when it was calm, there was some air movement.
He redefined the absence of wind to be an air speed of 1.8 metres per second, about as low a wind speed as a cup anemometer could measure. This led to more realistic values of equivalent temperature. Equivalent temperature was not universally used in North America until the 21st century; until the 1970s, the coldest parts of Canada reported the original Wind Chill Index, a three or four digit number with units of kilocalories/hour per square metre. Each individual calibrated the scale of numbers through experience; the chart provided general guidance to comfort and hazard through threshold values of the index, such as 1400, the threshold for frostbite. The original formula for the index was: W C I = ⋅ where: WCI = wind chill index, kcal/m2/h v = wind velocity, m/s Ta = air temperature, °C In November 2001, the United States, the United Kingdom implemented a new wind chill index developed by scientists and medical experts on the Joint Action Group for Temperature Indices, it is determined by iterating a model of skin temperature under various wind speeds and temperatures using standard engineering correlations of wind speed and heat transfer rate.
Heat transfer was calculated for a bare face in wind, facing the wind, while walking into it at 1.4 metres per second. The model corrects the measured wind speed to the wind speed at face height, assuming the person is in an open field; the results of this model may be approximated, to within one degree, from the following formula: The standard wind chill formula for Environment Canada is: T w c = 13.12 + 0.6215 T a − 11.37 v + 0.16 + 0.3965 T a v + 0.16 where Twc is the wind chill index, based on the Celsius temperature scale. When the temperature is −20 °C and the wind speed is 5 km/h, the wind chill index is −24. If the temperature remains at −20 °C and the wind speed increases to 30 km/h, the wind chill index falls to −33; the equivalent formula in US customary units is: T w c = 35.74 + 0.6215 T a − 35.75 v + 0.16 + 0.4275 T a v + 0.16 where Twc is the wind chill index, based on the Fahrenheit scale. Windchill temperature is defined only for temperatures at or below 1
Neshaminy Creek is a 40.7-mile-long stream that runs through Bucks County, rising south of the borough of Chalfont, where its north and west branches join. Neshaminy Creek flows southeast toward Bristol Township and Bensalem Township to its confluence with the Delaware River; the name "Neshaminy" originates with the Lenni Lenape and is thought to mean "place where we drink twice". This phenomenon refers to a section of the creek known as the Neshaminy Palisades, where the course of the water slows and changes direction at a right angle, nearly forcing the water back upon itself; these palisades are located in Dark Hollow Park, operated by the county, are flanked by Warwick Township to the south and Buckingham Township to the north. The watershed of the Neshaminy Creek covers an area of 236 square miles, 86 percent of, located in Bucks County and 14 percent in Montgomery County, it is part of the greater Delaware River watershed. The creek's course runs through suburban areas to the north of Philadelphia.
However, the course of the creek does run through a few sections of rural and semi-rural terrain, some forested areas remain. Neshaminy Creek passes through Tyler State Park and Neshaminy State Park. Neshaminy Creek has the distinction of having three tributaries named Mill Creek; the name seems to derive from the Lenape'Nesha-men-ning', loosely meaning'the place where we drink twice' or'two drinking places'. Older names were written as Nishambanach, Nishammis, Neshimineh, Neshaminia and others; this may refer to two springs near a village of the Lenape, since native people drink from a spring whenever available rather than from a stream. The location of the springs is unknown, but may have been two springs extant many years ago, not far from the confluence of the north and west branches. One was known at the time as the'Great Spring' and the other much smaller about 300 feet away and was said to have been near an old Indian trail; the Neshaminy was the first stream in Bucks County to have been crossed by bridges.
The Gordon Gazetteer of 1832 called it the Neshaminy River and stated that "over it, there are many fine wooden and stone bridges. The bridge nearest its mouth on the road to New York is a draw bridge-in private property, erected by the Messrs. Bassonet and Johnson, whose heirs and assigns levy tolls by virtue of the Act of Assembly 6th Sept. 1785. The Neshaminy as far as Barnsleys Ford was declared a public highway by Act of 9th March, 1771." The stream has seen a number of major floods. In the Mina flood of 1833, most of the bridges were washed away and was the highest flood known at that time. Compared to the flood of 16-17 July 1865, the 1833 flood was exceeded by 6 feet, rupturing the Turk Dam and destroying all of the bridges downstream; as the waters reached the Delaware River, the flow was so great as to reach the New Jersey shoreline leaving a large pile of debris and preventing shipping from traversing the river. The Neshaminy has been the subject of many artists over the years. Appalachian Division, Piedmont Province, Gettysburg-Newark SectionBeginning at the junction of the West Branch and North Branch Neshaminy Creeks, Neshaminy Creek begins in the Brunswick Formation, formed during the Jurassic and Triassic, which consists of mudstone and siltstone.
Mineralogy includes hornfels. West of Chalfont it passes into an extension of the Lockatong formation for a short distance, back into the Brunswick again to the Lockatong; the Lockatong Formation was deposited during the Triassic and consists of argillite, a layer of limestone. East of Chalfont, the Neshaminy flows into the Stockton Formation, laid during the Triassic, consisting of arkosic sandstone, shale and mudstone, it flows along the Stockton and Lockatong transition until the Neshaminy palisades, where it turns west in a few miles turns south into a region of felsic gneiss, which contains quartz, microcline and biotite. Appalachian Division, Piedmont Province, Upland SectionAfter passing Oakford, it passes through a small deposit of mafic gneiss, from the Precambrian, which contains calcic plagioclase, hypersthene or augite and hornblende. Appalachian Division, Piedmont Province and Intermediate Upland SectionNext, the stream passes into the Wissahickon Formation, a schist which has metamorphosed into a facies, containing garnet, staurolite and sillimanite.
The Wissahickon contains oligoclase-mica schist and augen gneiss', some feldspar. It passes through a region of Pensauken and Bridgeton Formations, from the Tertiary, but it has eroded through it to the underlying Wissahickon Formation. Both formations consis of quartz sand; the Neshaminy passes through the Trenton gravel formation, from the Quaternary, sand and clay-silt where it meets the Delaware River. Mill Creek Pine Run Ironworks Creek Newtown Creek Mill Creek Robin Run Watson Creek Lahaska Creek Little Neshaminy Creek Park Creek Cooks Run Mill Creek North Branch Neshaminy Creek Pine Run West Branch Neshaminy Creek Reading Creek Bensalem Township Bristol Township Buckingham Township Chalfont Doylestown Doylestown Township Hatfield Hulmeville Ivyland Langhorne Langhorne Manor Lansdale Lower Southampton Township Middletown Township New Britain New Britain Township Newtown Newtown Township Northampton Township Penndel Plumstead Township Upper Southampton Township Warminster Township Warwick Township Wrightstown Township Like other rivers and streams, the Neshaminy Creek poses a flooding threat to neighboring areas in ti
A ZIP Code is a postal code used by the United States Postal Service in a system it introduced in 1963. The term ZIP is an acronym for Zone Improvement Plan; the basic format consists of five digits. An extended ZIP+4 code was introduced in 1983 which includes the five digits of the ZIP Code, followed by a hyphen and four additional digits that reference a more specific location; the term ZIP Code was registered as a servicemark by the U. S. Postal Service, but its registration has since expired; the early history and context of postal codes began with postal district/zone numbers. The United States Post Office Department implemented postal zones for numerous large cities in 1943. For example: The "16" was the number of the postal zone in the specific city. By the early 1960s, a more organized system was needed, non-mandatory five-digit ZIP Codes were introduced nationwide on July 1, 1963; the USPOD issued its Publication 59: Abbreviations for Use with ZIP Code on October 1, 1963, with the list of two-letter state abbreviations which are written with both letters capitalized.
An earlier list in June had proposed capitalized abbreviations ranging from two to five letters. According to Publication 59, the two-letter standard was "based on a maximum 23-position line, because this has been found to be the most universally acceptable line capacity basis for major addressing systems", which would be exceeded by a long city name combined with a multi-letter state abbreviation, such as "Sacramento, Calif." along with the ZIP Code. The abbreviations have remained unchanged, with the exception of Nebraska, changed from NB to NE in 1969 at the request of the Canadian postal administration, to avoid confusion with the Canadian province of New Brunswick. Robert Moon is considered the father of the ZIP Code; the post office only credits Moon with the first three digits of the ZIP Code, which describe the sectional center facility or "sec center." An SCF is a central mail processing facility with those three digits. The fourth and fifth digits, which give a more precise locale within the SCF, were proposed by Henry Bentley Hahn Sr.
The SCF sorts mail to all post offices with those first three digits in their ZIP Codes. The mail is sorted according to the final two digits of the ZIP Code and sent to the corresponding post offices in the early morning. Sectional centers do not deliver mail and are not open to the public, most of their employees work the night shift. Mail picked up at post offices is sent to their own SCF in the afternoon, where the mail is sorted overnight. In the case of large cities, the last two digits coincide with the older postal zone number thus: In 1967, these became mandatory for second- and third-class bulk mailers, the system was soon adopted generally; the United States Post Office used a cartoon character, which it called Mr. ZIP, to promote the use of the ZIP Code, he was depicted with a legend such as "USE ZIP CODE" in the selvage of panes of postage stamps or on the covers of booklet panes of stamps. In 1971 Elmira Star-Gazette reporter Dick Baumbach found out the White House was not using a ZIP Code on its envelopes.
Herb Klein, special assistant to President Nixon, responded by saying the next printing of envelopes would include the ZIP Code. In 1983, the U. S. Postal Service introduced an expanded ZIP Code system that it called ZIP+4 called "plus-four codes", "add-on codes", or "add-ons". A ZIP+4 Code uses the basic five-digit code plus four additional digits to identify a geographic segment within the five-digit delivery area, such as a city block, a group of apartments, an individual high-volume receiver of mail, a post office box, or any other unit that could use an extra identifier to aid in efficient mail sorting and delivery. However, initial attempts to promote universal use of the new format met with public resistance and today the plus-four code is not required. In general, mail is read by a multiline optical character reader that instantly determines the correct ZIP+4 Code from the address—along with the more specific delivery point—and sprays an Intelligent Mail barcode on the face of the mail piece that corresponds to 11 digits—nine for the ZIP+4 Code and two for the delivery point.
For Post Office Boxes, the general rule is. The add-on code is one of the following: the last four digits of the box number, zero plus the last three digits of the box number, or, if the box number consists of fewer than four digits, enough zeros are attached to the front of the box number to produce a four-digit number. However, there is no uniform rule, so the ZIP+4 Code must be looked up individually for each box; the ZIP Code is translated into an Intelligent Mail barcode, printed on the mailpiece to make it easier for automated machines to sort. A barcode can be printed by the sender, it is better to let the post office put one on. In general, the post office uses OCR technology, though in some cases a human might have to read and enter the address. Customers who send bulk mail can get a discount on postage if they have printed the barcode themselves and have presorted the mai